UX-13 P4 review fixes (PR #146, comment 1887)

R1: first_start also needs a Store created at this boot (Store.fresh), so
    old never-started sites (both TEST-23 add-ons, one in shadow) stay on Home.
R2: a kettle skip after a fall says on the last step that the reading went down.
R3: the shadow switch goes only on the model the wizard posts, never into V.
R4: Home Assistant not answering is red on the last step.
R5: meter + solar + battery below -300 W flags a reversed battery sensor.
R6: the live checks say what to change and where.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/infra-pin

@@ -0,0 +1,2 @@
+# The admin/goodwe commit CI tests against. Bump: set to the full SHA of admin/goodwe release/1.0 HEAD (README.md, "CI and the infra pin").
+d637d0b1b13f1b863dc47e445e2ca4cf4a82fe10

.gitea/workflows/checks.yml

@@ -3,12 +3,35 @@
 # of real coverage including a wall-clock cadence test, and not one machine ever
 # ran them. Every merge here was a human reading a diff.
 #
-# ⚠️ NO `paths:` FILTER, AND ITS ABSENCE IS LOAD-BEARING. Branch protection on
-# release/1.0 requires the context `checks / unit (pull_request)`. Gitea leaves a
-# required context it never receives PENDING forever, so the moment this workflow
-# learns to sit a PR out, that PR becomes unmergeable. Condition a STEP if you
+# ⚠️ NO EVENT FILTER OF ANY KIND - NO `paths:`, AND SINCE CI-9 NO `branches:`
+# EITHER - AND THAT ABSENCE IS LOAD-BEARING. Branch protection on release/1.0
+# requires the context `checks / unit (pull_request)`. Condition a STEP if you
 # must; never the workflow.
 #
+# ⚠️ CI-01 WROTE THE REASON DOWN WRONG, AND THE WRONG REASON WAS THE SAFE-
+# SOUNDING ONE. It said an unreceived required context sits PENDING forever, so
+# a sat-out pull request becomes unmergeable - annoying, but fail-safe. That is
+# not what this Gitea does. MEASURED on Gitea 1.27.3, 2026-09-19, throwaway
+# PR #94: when a workflow exists but its event filter does not match, Gitea does
+# not stay silent. It POSTS the required context itself, with state `skipped`:
+#
+#   GET /api/v1/repos/admin/goodwe-addon/commits/<head sha>/statuses
+#     [{"status":"skipped","context":"checks / unit (pull_request)",
+#       "description":"Skipped","target_url":""}]      <- no run, no job, no url
+#
+#   GET /api/v1/repos/admin/goodwe-addon/commits/<head sha>/status
+#     {"state":"success","total_count":1}              <- the rollup LAUNDERS it
+#
+# and Gitea's merge gate accepts it. Same PR, same head sha, one status on it
+# and that status a skip, POST .../pulls/94/merge answered 409 `head out of
+# date` - the 409 being a deliberately wrong `head_commit_id` in the probe, i.e.
+# the request had ALREADY CLEARED BRANCH PROTECTION. The control, a required
+# context with no status at all, answered 405 `Not all required status checks
+# successful`. So the true failure mode is the exact inverse of the one written
+# here before: sitting a pull request out does not make it unmergeable, it makes
+# it MERGEABLE WITHOUT EVER BEING TESTED, and the badge says success while it
+# happens. Fail-open, not fail-closed. Do not reintroduce a filter here.
+#
 # ⚠️ THE RUNNER IS SHARED WITH THE OTHER REPO'S RIG. `goodwe-runner` on
 # 192.168.2.147 carries the labels `self-hosted` and `goodwe-rig` and is
 # registered `:host`, and it is the only runner there is - so this job wears the
@@ -23,9 +46,116 @@
 # that step; a green from this workflow is a claim about content that can land.
 name: checks
 
+# ⚠️ CI-9: `pull_request:` TAKES NO `branches:` LIST, ON PURPOSE. It used to
+# read `branches: [release/1.0, master]`, which meant a STACKED pull request -
+# one whose base is another feature branch rather than a release branch - did
+# not match, and so was skipped, laundered to `success`, and mergeable untested
+# by the mechanism described at the top of this file.
+#
+# ⚠️ AND RETARGETING DID NOT REPAIR IT, WHICH IS WHAT MADE THIS P1. The skip is
+# a COMMIT STATUS ON THE HEAD SHA, not a property of the pull request, so moving
+# the base afterwards leaves it exactly where it was. Observed live on PR #93
+# (2026-09-19): retargeted TEL-10 -> release/1.0, and the 10:05:00 `skipped`
+# stayed attached to head a6af332 with the rollup still reading success. It was
+# caught by a human who forced a real execution by reopening the pull request
+# (run 799, 10:56). Reproduced deliberately on throwaway PR #94: retargeted onto
+# a branch carrying a byte-identical copy of release/1.0's protection rule, and
+# the single `skipped` status survived the retarget unchanged - no new run, no
+# new status - and still cleared the gate.
+#
+# ⚠️ WHY NOT FIX THIS AT THE GATE INSTEAD, which would be the better place. It
+# cannot be done. Gitea's branch protection cannot express "this context must be
+# SUCCESS" as opposed to "this context must be PRESENT AND NOT FAILING". The
+# whole of its status-check vocabulary is two fields - `enable_status_check`
+# (bool) and `status_check_contexts` (a list of globs MATCHING CONTEXT NAMES) -
+# confirmed against this server's own schema at /swagger.v1.json, definitions
+# EditBranchProtectionOption and CreateBranchProtectionOption. There is no field
+# for the required STATE anywhere in either. The success/skip comparison lives
+# in Gitea's compiled code, so the only lever left is upstream of it: make sure
+# the context is never a skip in the first place. Hence this block.
+#
+# ⚠️ WHAT THIS COSTS, stated honestly, because it is a real trade. Every pull
+# request now runs the full suite, including the intermediate steps of a stack
+# that nobody intends to merge on its own. A run is ~8 minutes wall clock
+# (run 799: 7m55s) on a runner that is `capacity: 1` and shared with the other
+# repo's rig, so each extra run is ~8 minutes of slot that a rig campaign then
+# queues behind.
+#
+# SCALE OF THE NEW WORK, re-derived from the API and stated with its denominator,
+# because the first version of this paragraph had a made-up one. Counting the 93
+# pull requests that predate this ticket (#1..#93; CI-9's own #94..#98 excluded,
+# and note /pulls caps a page at 50, so this needs paging to see at all): 92 were
+# opened against release/1.0 and would have run anyway, and exactly ONE was
+# stacked - #2, TEL-01 -> SAFETY-04, closed unmerged, 2026-08-24. No pull request
+# has ever targeted `master`, so half the old filter was dead from the start.
+#
+# ⚠️ THAT 92 IS AN UPPER BOUND, NOT A CENSUS, and the reason is this very bug.
+# The API reports a pull request's CURRENT base, so one that was opened stacked
+# and later retargeted is recorded against its final base and is invisible here.
+# #93 is precisely that case - opened 2026-09-19T10:05:00 on TEL-10, retargeted,
+# merged into release/1.0 at 11:05:26 the same morning, under three hours before
+# CI-9 was opened - and it counts in the 92. So the true historical stacking rate
+# is somewhere above 1/93, and unmeasurable from here.
+#
+# The bill is therefore small today and grows with however much stacking the team
+# adopts. It is worth paying: the alternative is that the cheap case stays
+# untested and indistinguishable from the tested one.
+#
+# ⚠️ THIS DOES NOT CHANGE GITEA'S ACCEPTANCE OF A `skipped` REQUIRED CONTEXT -
+# that half is in its compiled code and is not reachable from this repository.
+# The CONSEQUENCE, though, is very largely closeable from here, and is closed:
+# after this edit there is nothing in this repository that produces a skip -
+# there is exactly one workflow file, it now has no event filter of any kind,
+# and the other candidate cause was MEASURED and is not one. The `guard the
+# trigger` step below then keeps it that way mechanically rather than by asking
+# the next editor to read this comment.
+#
+# ⚠️ READ THE BLIND SPOTS ON THAT STEP BEFORE TRUSTING THE SENTENCE ABOVE.
+# "Mechanically" holds only for a reintroduced filter that still names the
+# PR's own base. For blind spots 1 and 3 the defence IS this comment, because
+# the guard lives inside the workflow that a filter makes Gitea skip. Blind
+# spot 3 is the one that matters: a filter naming a branch THIS pull request
+# does not target is itself skipped, lands green and untested, and then every
+# subsequent pull request the filter DOES NOT NAME is skipped too. That is the
+# gate off, silently.
+#
+# ⚠️ THAT DIRECTION IS THE WHOLE POINT AND IT IS EASY TO WRITE BACKWARDS. A
+# pull request that MATCHES the filter still runs; it is the one the filter
+# excludes that Gitea sits out, reports `skipped`, and the rollup launders
+# into `success`. An earlier draft of this very clause said "matching it is
+# skipped", which is the inverse of the measurement and contradicted the
+# paragraph directly below.
+#
+# ⚠️ AND THE DANGEROUS ONE IS NOT `branches: [main]`, WHICH AT LEAST LOOKS
+# WRONG. It is `branches: [release/1.0]`, which looks like tightening onto the
+# protected branch and is what a careful person would write. Every day-to-day
+# pull request still runs and still goes green, so nothing appears broken -
+# and the only thing switched off is the `release/1.0` -> `master` release
+# PR, i.e. the one whose content reaches an installed system. SEC-2 made that
+# PR the mandated release path (docs/RELEASE.md), so this is now a live route
+# rather than a hypothetical one.
+#
+# Closing it needs a SECOND permanently unfiltered workflow posting its own
+# context, with that context added to the `status_check_contexts` of BOTH
+# `release/1.0` AND `master` - both carry the rule since SEC-2, and adding it
+# to one alone leaves the hole open on the other. A forge change, with the
+# owner.
+#
+# THE MEASUREMENT, because the obvious guess is wrong and was nearly written
+# here as fact. A skip-ci keyword in a commit message (`[skip ci]`, `[ci skip]`,
+# `[no ci]`, `[skip actions]`, `[actions skip]`) does NOT behave like a filter
+# miss. On throwaway PR #94, head b36effb, commit subject ending `[skip ci]`:
+#
+#   .../commits/b36effb/statuses   ->  []                  <- NO status, not a skip
+#   .../commits/b36effb/status     ->  {"state":"pending"} <- so the rollup is pending
+#   POST .../pulls/94/merge        ->  405 Not all required status checks successful
+#
+# i.e. skip-ci is FAIL-CLOSED - it withholds the context entirely, which is the
+# pending-forever behaviour CI-01's header wrongly attributed to a filter miss.
+# It blocks the merge rather than laundering it, so it needs no fix and no
+# app.ini change. Only the filter miss ever posted a `skipped`.
 on:
   pull_request:
-    branches: [release/1.0, master]
   workflow_dispatch:
 
 # ⚠️ NO `concurrency:` BLOCK, AND ITS ABSENCE IS AS LOAD-BEARING AS THE MISSING
@@ -156,8 +286,9 @@ jobs:
         run: |
           set -eu
           rm -rf "$WS" && mkdir -p "$WS/goodwe-addon" && cd "$WS/goodwe-addon"
-          git init -q .
-          git remote add origin "$(echo "$URL" | sed "s#://#://x-access-token:${TOKEN}@#")"
+          git init -q . && git remote add origin "$URL"
+          # Token as an env-set header: not in argv or .git/config (TOOL-9).
+          export GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=http.extraHeader GIT_CONFIG_VALUE_0="Authorization: token $TOKEN"
           if [ -n "$PRNUM" ]; then
             # Two fetches, not one, so that a failure to reach either ref fails
             # HERE with the ref in the message, rather than inside the merge
@@ -224,6 +355,165 @@ jobs:
             exit 1
           fi
 
+      # ⚠️ THE GUARD ON THE TRIGGER. THIS STEP EXISTS BECAUSE PROSE ALREADY
+      # FAILED IN THIS FILE, ONCE, FOR TWENTY DAYS.
+      #
+      # `git show 9c1a23328a` is CI-01's first commit. It shipped the header
+      # "⚠️ NO `paths:` FILTER, AND ITS ABSENCE IS LOAD-BEARING" and the line
+      # `branches: [release/1.0, master]` IN THE SAME COMMIT, EIGHTEEN LINES
+      # APART. The comment forbade one kind of event filter while the code
+      # directly above the job carried another, and nobody caught it through 84
+      # merges until the gate let a stacked pull request through. So the whole of
+      # CI-9's fix rests on an invariant - "checks.yml has no event filter" -
+      # that has already been silently violated in this exact file by the person
+      # who wrote the warning against violating it. A louder comment is not a
+      # remedy for that. A red step is.
+      #
+      # WHY THIS CAN WORK AT ALL, given CI-9 rejected the card's option 3 (a step
+      # that detects its own workflow having been skipped) as impossible. That
+      # option is impossible because a skipped workflow runs no steps, so there
+      # is nothing alive to notice. This is the different, tractable case: it
+      # fires on the pull request that REINTRODUCES a filter, and it does so
+      # whenever the filter being reintroduced STILL NAMES THAT PULL REQUEST'S
+      # OWN BASE - the ordinary case, because a filter put back by hand names
+      # the release branch people are actually targeting. The edit then has to
+      # get past this step before it can start causing skips. It is a ratchet,
+      # not a skip detector.
+      #
+      # ⚠️ AND IT IS THE HEAD'S WORKFLOW THAT DECIDES WHETHER ANYTHING RUNS, NOT
+      # THE BASE'S. An earlier draft of this comment claimed the reintroducing
+      # pull request "is still graded by the unfiltered workflow which is on the
+      # base today". That was wrong, it contradicted the checkout step's own note
+      # a few lines below, and the error was not cosmetic: it made this step
+      # sound like an unconditional ratchet, which is exactly the false comfort
+      # CI-9 exists to stamp out. MEASURED on PR #101 - head carrying a filter
+      # that excludes the base, base carrying the unfiltered workflow - and the
+      # result was no run at all, the context posted `skipped`, the rollup
+      # reading `success`, and the gate CLEARED (409). Gitea takes the workflow
+      # file from refs/pull/<n>/head, so a head that filters itself out is simply
+      # never graded, and nothing on the base can reach out and stop it. That is
+      # what blind spot 3 below is made of.
+      #
+      # WHAT IT INSPECTS is the MERGED tree in $WS - the content that would
+      # actually land on the base - not the branch tip and not the copy of this
+      # file that Gitea used to decide whether to run. Those are three different
+      # trees here (see the long note on the checkout step) and only the merged
+      # one is the thing being authorised.
+      #
+      # ⚠️ THREE ACKNOWLEDGED BLIND SPOTS. NOT ONE OF THEM IS CLOSEABLE FROM
+      # INSIDE THIS FILE, and the reason is the same in all three: each is a case
+      # where THIS WORKFLOW IS ITSELF THE THING THAT GETS SKIPPED, and a guard
+      # that lives inside a skipped workflow does not run. Closing them needs a
+      # SECOND, permanently unfiltered workflow whose own context is added to
+      # release/1.0's `status_check_contexts`, so that something survives to
+      # report when this file is sat out. That is a forge change and the
+      # repository owner's decision; it is being put to them separately and is
+      # deliberately NOT held as a blocker on CI-9.
+      #
+      #   1. A reintroduced `paths:` filter crafted to exclude the reintroducing
+      #      pull request's OWN diff would skip that pull request, so this step
+      #      would not run to object to it.
+      #
+      #   2. An edit that lands on a feature branch through a stacked pull
+      #      request is graded by the HEAD's workflow, so a filter already
+      #      present in the head hides the edit from this step - until that
+      #      branch is proposed for release/1.0, where (unless it is case 3) the
+      #      base matches the reintroduced filter and this step runs and bites.
+      #      Caught at the release boundary, which is the boundary that matters.
+      #
+      #   3. ⚠️ THE WORST OF THE THREE, AND WORSE THAN BOTH OF THE OTHERS PUT
+      #      TOGETHER: a reintroduced `branches:` filter that simply DOES NOT
+      #      NAME THE BASE escapes this step entirely, because the pull request
+      #      carrying it is itself skipped. It takes no craft and no malice to
+      #      write - `branches: [main]` copied out of a GitHub template, or a
+      #      tidy-up to `[master]`, a branch that NO pull request in this
+      #      repository's history has ever targeted - and it arrives as a
+      #      skipped, laundered, untested merge into release/1.0.
+      #
+      #      What makes it categorically worse is what happens the moment after.
+      #      Once that file is ON release/1.0, every subsequent pull request is
+      #      graded against it and every one of them is skipped too. This is not
+      #      the stacked case leaking through a crack; it is the gate off
+      #      completely, for everything, silently, with every badge green. The
+      #      only thing standing between the repository and that state today is
+      #      a human reading this file - which is precisely the kind of defence
+      #      this step exists because it has already failed once (9c1a23328a).
+      #
+      # It is deliberately a FAILURE and not a warning: a warning would leave
+      # the required context green, which is the precise defect CI-9 is about.
+      - name: guard the trigger - refuse a checks.yml that has regained an event filter
+        run: |
+          set -eu
+          f="$WS/goodwe-addon/.gitea/workflows/checks.yml"
+          test -f "$f" || { echo "checks.yml is missing from the merged tree."; exit 1; }
+          # Walk the top-level `on:` block of the MERGED file. Full-line comments
+          # at column 0 are skipped outright - this file's own prose quotes
+          # `paths:` and `branches:` many times and must not trip its own guard -
+          # and an inline `#` is trimmed from any line that is kept.
+          bad=$(awk '
+            function scan(t) {
+              sub(/#.*/, "", t)
+              if (t ~ /(^|[^A-Za-z0-9_-])(branches|branches-ignore|paths|paths-ignore|tags|tags-ignore|types)[[:space:]]*:/)
+                return 1
+              return 0
+            }
+            /^[[:space:]]*#/ { next }
+            /^("on"|'"'"'on'"'"'|on)[[:space:]]*:/ {
+              inon = 1
+              rest = $0; sub(/^[^:]*:/, "", rest)
+              if (scan(rest)) print NR ": " $0
+              next
+            }
+            inon == 1 {
+              if ($0 ~ /^[[:space:]]*$/) next
+              if ($0 ~ /^[[:space:]]/) { if (scan($0)) print NR ": " $0; next }
+              inon = 0
+            }
+          ' "$f")
+          if [ -n "$bad" ]; then
+            echo "REFUSED: checks.yml has regained an event filter in its \`on:\` block."
+            echo "$bad"
+            echo
+            echo "  A filter means some pull request stops matching this workflow. Gitea does"
+            echo "  not stay silent about a workflow it sits out - it posts the required context"
+            echo "  \`checks / unit (pull_request)\` itself with state \`skipped\`, the combined"
+            echo "  status rolls that up as \`success\`, and the merge gate ACCEPTS it. That is"
+            echo "  CI-9: a pull request merged on a workflow that never ran a step. It was"
+            echo "  reproduced by merging PR #96 for real through a protected branch."
+            echo
+            echo "  Branch protection cannot save you here - it can require that a context is"
+            echo "  PRESENT, never that it is SUCCESS - so the filter is the whole defence."
+            echo "  If you genuinely need to narrow what runs, condition a STEP, never the"
+            echo "  workflow. See the \`on:\` block's comments for the measurements."
+            exit 1
+          fi
+          echo "OK: the \`on:\` block of the merged checks.yml carries no event filter."
+
+      # CI-12: the infra repo at the ONE pinned commit in .gitea/infra-pin (read
+      # from the merged tree), as the sibling test_freeze.py looks for. Any
+      # failure here fails the job; the tests step below refuses the stub.
+      - name: check out admin/goodwe at the pin in .gitea/infra-pin
+        env:
+          URL: ${{ github.server_url }}/admin/goodwe.git
+          # Read access to admin/goodwe only; this job's own token cannot see it.
+          TOKEN: ${{ secrets.INFRA_READ_TOKEN }}
+        run: |
+          set -eu
+          # `|| true`: under pipefail a missing or comment-only pin would skip the FAIL line (TOOL-9).
+          PIN=$(grep -v '^#' "$WS/goodwe-addon/.gitea/infra-pin" | tr -d '[:space:]') || true
+          echo "$PIN" | grep -Eq '^[0-9a-f]{40}$' || { echo "FAIL: .gitea/infra-pin holds '$PIN', not a full 40-hex SHA."; exit 1; }
+          test -n "$TOKEN" || { echo "FAIL: secret INFRA_READ_TOKEN is not available to this run (a fork PR?)."; exit 1; }
+          rm -rf "$WS/goodwe" && mkdir -p "$WS/goodwe" && cd "$WS/goodwe"
+          git init -q .
+          # The token goes in a header via env: not in argv, and not in .git/config,
+          # which is mounted into the tests' container and outlives a failed job.
+          GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=http.extraHeader GIT_CONFIG_VALUE_0="Authorization: token $TOKEN" \
+            git fetch -q "$URL" "$PIN" || { echo "FAIL: could not fetch admin/goodwe at $PIN."; exit 1; }
+          git -c advice.detachedHead=false checkout -qf FETCH_HEAD
+          test "$(git rev-parse HEAD)" = "$PIN"
+          test -f sim/hwsim.py || { echo "FAIL: admin/goodwe@$PIN has no sim/hwsim.py."; exit 1; }
+          echo "infra: admin/goodwe @ $(git log --oneline -1)"
+
       - name: build the test image (shipped deps, from apk - see .gitea/ci/Dockerfile)
         run: |
           set -eu
@@ -244,16 +534,9 @@ jobs:
       # shorter timeout - a 60 s limit was tried during CI-01 and reported
       # exactly the false hang the docstring predicts.
       #
-      # ⚠️ WHAT THIS RUN DOES NOT COVER, stated because a pass here would
-      # otherwise over-claim. test_freeze.py's third section wants the infra
-      # repo's `sim/hwsim.py` to drive a real HTTP meter through the real
-      # transport. admin/goodwe is PRIVATE (checked via the API) and this
-      # workflow's GITHUB_TOKEN is minted for THIS repository only, so hwsim is
-      # absent here and `find_hwsim()` returns None. The rest of the file runs
-      # and passes. It does so SILENTLY - the file prints nothing to say the
-      # hwsim section was skipped - so "test_freeze.py: PASS" below is a weaker
-      # claim than it looks. That belongs to whoever owns test_freeze.py next;
-      # naming it here is the least this gate can do about it.
+      # test_freeze.py part 3 runs against the real `sim/hwsim.py` from the
+      # checkout above; GOODWE_REQUIRE_HWSIM=1 makes it fail rather than use its
+      # stub (CI-12). Lines a test prints with a `CI: ` prefix are echoed on PASS.
       # ⚠️ PYTHONDONTWRITEBYTECODE=1 IS BELT AND BRACES, NOT A FIX FOR A LIVE
       # HOLE. TEST-15 measured this runner's actual exposure and found none: the
       # checkout below is bind mounted `:ro`, so the interpreter physically
@@ -269,7 +552,7 @@ jobs:
       - name: the add-on's own tests
         run: |
           set -eu
-          docker run --rm -e PYTHONDONTWRITEBYTECODE=1 -v "$WS:/w:ro" goodwe-addon-checks:1 sh -eu -c '
+          docker run --rm -e PYTHONDONTWRITEBYTECODE=1 -e GOODWE_REQUIRE_HWSIM=1 -v "$WS:/w:ro" goodwe-addon-checks:1 sh -eu -c '
             cd /w/goodwe-addon/goodwe_controller
             set -- test_*.py
             if [ "$1" = "test_*.py" ]; then
@@ -282,6 +565,7 @@ jobs:
               start=$(date +%s)
               if python3 "$f" > /tmp/out 2>&1; then
                 echo "PASS  $f  ($(( $(date +%s) - start ))s)"
+                grep "^CI: " /tmp/out || true
               else
                 echo "FAIL  $f  ($(( $(date +%s) - start ))s)"
                 tail -40 /tmp/out

.gitea/workflows/infra-pin.yml

@@ -0,0 +1,46 @@
+# CI-12: goes red when admin/goodwe release/1.0 has moved past .gitea/infra-pin.
+# It runs on add-on activity only; admin/goodwe's own `addon-pin` workflow
+# covers a move of release/1.0 there. Deliberately NOT a required check: it
+# reports; `checks / unit` stays the only gate. How to bump: README.md,
+# "CI and the infra pin".
+name: infra-pin
+
+on:
+  pull_request:
+  push:
+    branches: [release/1.0]
+
+jobs:
+  fresh:
+    runs-on: [self-hosted, goodwe-rig]
+    timeout-minutes: 30   # seconds of work; the rest is queueing for the shared slot
+    steps:
+      - name: compare .gitea/infra-pin with admin/goodwe release/1.0
+        env:
+          SELF: ${{ github.server_url }}/${{ github.repository }}.git
+          INFRA: ${{ github.server_url }}/admin/goodwe.git
+          TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          INFRA_TOKEN: ${{ secrets.INFRA_READ_TOKEN }}   # admin/goodwe is private
+        run: |
+          set -eu
+          D=$(mktemp -d) && trap 'cd / && rm -rf "$D"' EXIT && cd "$D"
+          git init -q .
+          # The pin of the commit this event is about (the PR head, or the push).
+          # Token as an env-set header: not in argv or .git/config (TOOL-9).
+          GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=http.extraHeader GIT_CONFIG_VALUE_0="Authorization: token $TOKEN" \
+            git fetch -q --depth 1 "$SELF" "$GITHUB_SHA" || { echo "FAIL: could not fetch $GITHUB_SHA here."; exit 1; }
+          # `|| true`: under the runner's pipefail a missing or comment-only pin
+          # would stop here on git's error instead of the FAIL line below (TOOL-9).
+          PIN=$(git show FETCH_HEAD:.gitea/infra-pin | grep -v '^#' | tr -d '[:space:]') || true
+          test -n "$PIN" || { echo "FAIL: .gitea/infra-pin is missing at $GITHUB_SHA, or holds only comments."; exit 1; }
+          test -n "$INFRA_TOKEN" || { echo "FAIL: secret INFRA_READ_TOKEN is not available to this run (a fork PR?)."; exit 1; }
+          # Header via env, as in checks.yml: the token stays out of argv.
+          HEAD=$(GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=http.extraHeader GIT_CONFIG_VALUE_0="Authorization: token $INFRA_TOKEN" \
+            git ls-remote "$INFRA" refs/heads/release/1.0 | cut -f1) || true
+          test -n "$HEAD" || { echo "FAIL: could not read admin/goodwe release/1.0."; exit 1; }
+          if [ "$PIN" != "$HEAD" ]; then
+            echo "STALE: .gitea/infra-pin is $PIN but admin/goodwe release/1.0 is $HEAD."
+            echo "       Test against $HEAD and bump the pin (README.md, \"CI and the infra pin\")."
+            exit 1
+          fi
+          echo "OK: .gitea/infra-pin $PIN is admin/goodwe release/1.0 HEAD."

FIELD-GUIDE.md

@@ -4,6 +4,10 @@ The guide technicians carry is the PDF:
 
 **`docs/GoodWe-RS485-Field-Guide.pdf`** — 10 pages, A4, print it double-sided.
 
+⚠️ **Outdated: it is v0.1.0.** Its `slew_w` row is corrected in `build_guide.py`
+and `field-guide.html`, but the PDF has not been rebuilt (see below). Where the
+guide disagrees with `goodwe_controller/DOCS.md`, DOCS.md wins.
+
 It covers, in the order the work is done: pre-visit checks, hardware, firmware,
 add-on install and configuration, how to read the Web UI, the six commissioning
 gates, the e-stop (and the statement a site without one must sign), proving a
@@ -18,7 +22,8 @@ copy cannot drift from the PDF someone is holding in a cellar.
 python3 docs/build_guide.py     # regenerates field-guide.html and the PDF
 ```
 
-Requires Chrome or Chromium (used headless for print-to-PDF). Screenshots live
+Requires Chrome or Chromium (used headless for print-to-PDF); `CHROME` in the
+script is a Windows path, so edit it on any other machine. Screenshots live
 in `docs/img/` and are base64-embedded, so `field-guide.html` is standalone.
 
 ⚠️ **Every section must stay under the A4 printable height** (1039 px at 96 dpi

README.md

@@ -30,9 +30,11 @@ goodwe_controller/         the add-on
                            returns, run against its own release image
 firmware/goodwe-master.yaml  ESPHome config for the T-CAN485
 estop/rs485_log.py           optional RS485 e-stop / bus witness
-docs/GoodWe-RS485-Field-Guide.pdf  the guide techs carry (10pp, A4)
+docs/GoodWe-RS485-Field-Guide.pdf  the guide techs carry (10pp, A4; outdated)
 docs/build_guide.py          its single source - rebuilds the HTML and PDF
 FIELD-GUIDE.md             how to edit and rebuild the guide
+docs/RELEASE.md            how a change reaches the battery - `master` is
+                           protected, releases go via PR from `release/1.0`
 ```
 
 **Picking this up after a break? Read `HANDOVER.md` first** — current state,
@@ -48,6 +50,9 @@ https://gittea.kammenstraatha.duckdns.org/admin/goodwe-addon
 
 then install **GoodWe RS485 Controller**.
 
+Then turn on **Watchdog** on the add-on's Info tab — see
+[Before you start](goodwe_controller/DOCS.md#before-you-start).
+
 ⚠️ **The repository must be PUBLIC for this to work.** Home Assistant clones it
 anonymously; against a private repo the store shows nothing and gives no useful
 error. If it must stay private, install locally instead: copy
@@ -77,8 +82,8 @@ machine itself dying:
 2. **Wind-down before firmware updates** — 0 W written before the update starts.
 3. **RS485 e-stop (optional)** — writes 0 W after 30 s of total bus silence.
 
-Sites sold without the e-stop must have the acknowledgement in `FIELD-GUIDE.md`
-§10 signed.
+Sites sold without the e-stop must have the client acknowledgement in the field
+guide (Step 7b) signed.
 
 ## Development
 
@@ -100,6 +105,12 @@ has the mechanism, the measurement, and what the flags do not do. They are not u
 each assertion corresponds to a rule whose absence produced an observed failure
 on real hardware, and the comments in `control.py` say which.
 
+### CI and the infra pin
+
+CI (`.gitea/workflows/checks.yml`) runs every `test_*.py`, with `admin/goodwe` checked out next to this repo at the commit in `.gitea/infra-pin`, so `test_freeze.py` grades against the real `sim/hwsim.py`. If that checkout fails, the job fails. The local stub is used only in local runs, and it prints `STUB USED` when it is.
+The pin tracks `admin/goodwe` **release/1.0**, not master. Two non-required checks go red when release/1.0 has moved past the pin: `infra-pin / fresh` here, on any add-on PR or push to release/1.0, and `addon-pin / fresh` in `admin/goodwe`, on every push to its release/1.0. Nothing re-runs `addon-pin` after a bump, so it stays red on that admin/goodwe commit; `infra-pin / fresh` green on the bump is the all-clear.
+**Bump the pin** whenever either is red. Set `.gitea/infra-pin` to the new release/1.0 SHA (`git ls-remote <gitea>/admin/goodwe.git refs/heads/release/1.0`) in a PR, and let `checks / unit` grade the tests against it. CI reads `admin/goodwe` with the Actions secret `INFRA_READ_TOKEN`.
+
 ## Compatibility
 
 **Check the serial number, not the model name.** Characters 6-8 of the serial are

STYLE.md

@@ -0,0 +1,64 @@
+# STYLE.md - how user-facing text is written (UX-08)
+
+This applies to everything a home owner or installer reads: notifications, phone pushes, the add-on page, refusals, add-on log lines at WARNING and above, and the names and descriptions of options. It is enforced by `goodwe_controller/test_messages.py`. Its allowlist is empty since phase 2d and its cap is 0: a new string that breaks the rule fails the test.
+
+## 1. Shape
+- **Title**: at most 5 everyday words. It says what is wrong ("Meter reading may be stuck"). No "GoodWe:" prefix, no full stop.
+- **Body**: **one sentence** of at most 25 words, saying what happened and what to do. A **red alarm** may use up to **3 sentences** (70 words, each sentence at most 30 words), so that no action a person must take is lost.
+- **Details**: the last line links to the add-on documentation and names the section with the rest: `Details: add-on documentation, section "<title>" under Notifications.` Background, figures, reason codes and history go there or into the log, never into the body.
+- **Status row**: one sentence of at most 15 words. A **red** row may use up to 3 sentences (30 words), like a red alarm. It shows the live numbers the reader acts on and never an HA entity id. **Banner**: at most 12 words. **Refusal**: at most 30 words, naming the setting by its label and then its key, as `messages.setting()` writes it: “Inverter rating” (max_w), or “Inverter rating” for inverter-b (inverters.max_w) for one inverter in the list. **Option name**: at most 6 words, not counting the group prefix. **Option description**: at most 30 words. Where a value comes from belongs in DOCS.md.
+- **Plan line** (UX-13 Home screen: the plan, tooltips, a battery's "now" line): at most 2 sentences, each at most 12 words. Words from `app/homeview.py`, checked by `test_messages.py` part 8.
+- **Log line** (WARNING/ERROR): one line of at most 25 words **as logged**, with any built text filled in. Log lines stay in English and are not translated. A line that reports a safety reason gives one plain sentence and the reason's code (`STALE_READING`, `OUTPUT_CLAMP`), the evidence an installer searches for. The reason itself, with its figures and limits, goes on a DEBUG line right after it and into the action log, never onto the WARNING/ERROR line. It keeps the shape of a red alarm: at most 3 sentences of at most 30 words. The line as logged has no semicolon, banned word, capitals, "1 times" or "(s)". `test_messages.py` part 6 builds every such text with the real code and checks it, and lists the few non-safety families still over 25 words. A line that repeats every cycle is DEBUG. INFO lines carry no section numbers, ISO timestamps or capitals.
+- **Refusal length is counted as shown**: a setting placeholder counts as its label and key, and the long cases are driven through the validator (`test_messages.py` part 3).
+- **Event line** under the buttons: the plain words of `messages.hint()`, like a green row. The add-on's own action log stays technical and is not shown on the page. Installers read it as `events` in the `status` JSON.
+- **Sentences**: one idea each, active voice, present tense, with nothing nested in brackets and no semicolons (a semicolon is a second sentence in disguise). These translate well into Dutch and French.
+
+## 2. Numbers
+Use a number only if it helps the reader act, for example the peak limit, or what was asked and what was sent in a fault report. Write it the way `app/messages.py` does: `5 000 W`, `20 %`, `10 minutes`, `14:05`.
+
+## 3. Severity
+Severity is shown by the title and the colour, never by CAPITALS or by words like "BUG SIGNAL".
+
+| Level | Colour | When |
+|---|---|---|
+| alarm | red | Control stopped, money or energy lost now, a fault, or a person must act now. Up to 3 sentences. |
+| warning | orange | Control is still running, but something needs a look. 1 sentence. |
+| info | grey | No action needed. 1 sentence. |
+| resolved | green | An earlier alarm or warning has cleared. 1 sentence. |
+
+A rewrite never changes an alarm's severity, `notification_id` or cadence.
+
+## 4. Words - the same word for the same thing everywhere
+A setting is named by its label in `translations/en.yaml`, in quotes when it sits mid-sentence (“Inverter rating”). The words below match those labels. If a label changes, change it here and in `app/messages.py` in the same change.
+
+| Say | Not |
+|---|---|
+| the add-on (who decides), control (what it does: "start control", "Control: last ran …") | controller, loop, planner |
+| battery | pack, BMS pack |
+| inverter, or its name | unit, device, actuator |
+| meter | P1 feed, telegram |
+| peak limit / this month's peak | ceiling, capaciteitstarief, billed quarter |
+| 15-minute period | quarter |
+| battery level (setting: “Battery level entity”) | SoC, state of charge, charge level |
+| battery cut-out level, or cut-out level next to "battery" (setting: “Battery cut-out level”) | BMS floor, `bms_soc_floor` |
+| peak reserve (setting: “Peak reserve”) | `peak_soc_floor`, EMS floor, "peak guard will not discharge below" |
+| “Inverter rating” (the setting) | `max_w`, rail, inverter rating as a fact about the hardware |
+| solar production, solar entity (settings: “Solar production entity”, “Solar production entities, per inverter”, “Reversed-sign solar entities”) | PV, reversed-sign list, single sensor setting |
+| “Where the meter reading comes from” | meter source |
+| “Grid power entity”; entity for any Home Assistant sensor a setting points at | grid power sensor, sensor setting |
+| draw the battery down, give power | discharge, discharging |
+| control is stopped / every inverter is set to 0 W | failsafe, trip, latch, parked |
+| safety stop (a stop that only starting control clears) | failsafe latch |
+| software fault | BUG SIGNAL |
+| control board | master, ESP32 |
+| power request, what the add-on asks | command, setpoint (on the page) |
+| the power went the wrong way | sign disagreement, command and meter point opposite ways |
+| check for inverters working against each other | circulating power check |
+| month peak, 15-minute periods measured | billed quarter, banked, soft limit, open block |
+| shadow mode | a mode that makes every decision but commands 0 W. The name is kept. In shadow mode a text says what the add-on **would** send, never that it sent it. |
+
+**Banned in titles and bodies** (the test fails on them): SAFETY-/TARIFF-/TEL-/CFG-/FW-/HW-nn and other card ids, integrator, anti-windup, windup, clamp, clamped, saturated, BUG SIGNAL, latch, latched, arbiter, allocator, register, `0x…`, layer 1/2/3, heartbeat, watchdog, telegram, ACK, CRC, OTA, Modbus, planner, `§n`, file names, IP addresses, option keys in snake_case, **HA entity ids**, and runs of 2 or more CAPITALISED words.
+
+HA entity ids are allowed only in refusals and validator messages, where the installer has to find that entity. They are never allowed in alarms or status rows.
+
+**Glossary.** DOCS.md "Words used on this page" explains, once, the words a home owner meets without context: control board, isolator, Developer Tools, shadow mode, safety stop, peak limit, peak guard, peak reserve and cut-out level. A home-owner text may use them without explaining them again. Card ids stay out of DOCS.md headings: they go on a *For installers* line under the heading.

docs/RELEASE.md

@@ -0,0 +1,116 @@
+# Releasing — how a change reaches the battery
+
+`master` is the **default branch**, and the default branch is what the Home
+Assistant Supervisor clones when it installs or updates this add-on. Whatever
+sits on `master` is what runs on a real 5 kW inverter. Treat a push to `master`
+as a deployment, because that is what it is.
+
+---
+
+## 1. `master` is protected — releases go through a pull request
+
+Until 2026-09-23 `master` had **no protection of any kind**. Every gate this
+repo built (CI-01, CI-9) sat on `release/1.0`, the branch that does *not* ship.
+On 2026-09-22 version 0.10.1 went straight onto `master` — no pull request, no
+CI run, no reviewer — and it succeeded (commit `0f14c2a`, the only commit on
+`master` that carries no `(#NN)` merge suffix). SEC-2 closed that.
+
+**The release path is now:**
+
+1. Merge the work into `release/1.0` as usual, via a pull request that goes
+   green. Bump `version:` in `goodwe_controller/config.yaml` on that branch —
+   the Supervisor keys the built image by `version:`, so without a bump nothing
+   is offered and nothing changes.
+2. Open a pull request **`release/1.0` → `master`**. Do not push to `master`;
+   it will be refused by the pre-receive hook:
+
+   ```
+   remote: error: Not allowed to push to protected branch master
+   ! [remote rejected] ... (pre-receive hook declined)
+   ```
+
+3. Wait for `checks / unit (pull_request)` to go **green** on that pull request.
+   The workflow in `.gitea/workflows/checks.yml` carries **no `branches:`
+   filter**, so a `master` base matches and a real run happens — verified on
+   throwaway PR #107 (base `master`), which queued a genuine run.
+
+   ⚠️ Green means green. A `skipped` status is laundered into a `success`
+   rollup by this Gitea and the merge gate accepts it — see the long note at
+   the top of `.gitea/workflows/checks.yml`. Never add an event filter there.
+
+4. Merge the pull request. `required_approvals` is **0**, so a green check is
+   the whole gate; there is no second pair of eyes unless someone asks for one.
+
+5. **Reload the store.** Merging to `master` does not, by itself, offer the
+   update. The Supervisor only sees the new version after:
+
+   ```bash
+   ssh root@192.168.2.158 "ha store reload && ha addons update local_goodwe_controller"
+   ```
+
+   Until `ha store reload` runs, the add-on page still shows the old version
+   and the release looks like it did nothing.
+
+Note that `release/1.0` is normally an *ancestor* of `master` between releases,
+so a `release/1.0 → master` pull request is empty until new commits land on
+`release/1.0`. That is expected; it means there is nothing to release yet.
+
+---
+
+## 2. Branch protection — before and after SEC-2
+
+Forge is Gitea at `192.168.2.147:3000`, repo `admin/goodwe-addon`. Read it back
+with `GET /api/v1/repos/admin/goodwe-addon/branch_protections`.
+
+**Before (2026-09-23):**
+
+| branch | protected | status check required | context | approvals |
+|---|---|---|---|---|
+| `master` (default) | **no rule at all** | — | — | — |
+| `release/1.0` | yes | yes | `checks / unit (pull_request)` | 0 |
+
+**After:**
+
+| branch | protected | status check required | context | approvals |
+|---|---|---|---|---|
+| `master` (default) | yes | yes | `checks / unit (pull_request)` | 0 |
+| `release/1.0` | yes (unchanged) | yes | `checks / unit (pull_request)` | 0 |
+
+Both rules are otherwise identical: `enable_push: false`,
+`enable_force_push: false`, `block_admin_merge_override: true`, no whitelists,
+no file patterns. `required_approvals` stays at **0** on purpose — raising it
+would block the review agent from merging, and nobody asked for it.
+
+The default branch was **not** changed. Changing it would change what the
+Supervisor clones, which is a different decision from this one.
+
+### How the gate was proven to actually bite
+
+A protection rule on this forge can *appear* satisfied while having checked
+nothing, so the rule was tested rather than trusted. The discriminator is a
+merge `POST` carrying a deliberately wrong `head_commit_id`: Gitea evaluates
+branch protection *before* it checks the head, so
+
+* `409 head out of date` → the request **cleared** protection;
+* `405 Not all required status checks successful` → protection **refused** it.
+
+Read the *message*, not just the code: `405` is also returned as
+`Please try again later` for a pull request with **no commits**, which has
+nothing to do with protection. An empty pull request on an unprotected base
+gives that same `405` (verified, throwaway PR #110), so an empty
+`release/1.0 → master` reports it too.
+
+Validated against a control on an unprotected base (PR #106), which answered
+`409` while its check was still pending — i.e. protection was no obstacle
+there. On `master` (PR #107) the same probe answered `405` while pending, and
+`409` once the check was genuinely green. A direct `git push` to `master` was
+rejected by the pre-receive hook with `master`'s SHA unmoved.
+
+---
+
+## 3. Rolling back
+
+There is no force-push escape hatch: `enable_force_push` is `false` on both
+branches. To undo a bad release, land a revert on `release/1.0`, bump the
+version again, and take it through §1. The `/addons/` rollback for the
+reference install is in `HANDOVER.md`.

docs/build_guide.py

@@ -95,7 +95,7 @@ figcaption { font-size:9pt; color:#5b6169; margin-top:1.2mm; }
 <div class="page" id="p1">
   <div class="hdr">
     <div><h1>GoodWe RS485 Controller</h1>
-         <div class="sub">Field installation &amp; commissioning guide — v0.1.0</div></div>
+         <div class="sub">Field installation &amp; commissioning guide — v0.1.0, <b>outdated</b>: where it disagrees with DOCS.md, DOCS.md wins</div></div>
     <small>Installer copy</small>
   </div>
 
@@ -503,7 +503,7 @@ figcaption { font-size:9pt; color:#5b6169; margin-top:1.2mm; }
   <table>
     <tr><th style="width:30mm">Setting</th><th style="width:16mm">Value</th><th>Reason</th></tr>
     <tr><td><code>gain</code></td><td>0.6</td><td>Inverter needs 3–6 s to settle (1.4 s dead time, 94 % by 3.3 s) against a ~5 s cycle. <b>At the limit — do not raise</b></td></tr>
-    <tr><td><code>slew_w</code></td><td>1000</td><td>Most of a correction in the first cycle without running far ahead of the hardware</td></tr>
+    <tr><td><code>slew_w</code></td><td>0</td><td>0 follows the rail (<code>max_w</code>&nbsp;/&nbsp;9). A faster fixed value is <b>refused at startup</b> (SAFETY-39) — see DOCS.md</td></tr>
     <tr><td><code>deadband_w</code></td><td>15</td><td>Measured residual: mean 15.4 W, max 27 W. At 10 W the command never rests</td></tr>
     <tr><td><code>saturation_w</code> / <code>cycles</code></td><td>500 / 3</td><td>Divergence = inverter at a limit → magnitude may fall, never rise. <b>The 3-cycle term is essential</b>: tested instantly it fires on every large correction</td></tr>
     <tr><td><code>step_w</code></td><td>10</td><td>Register is 1 W but response lands on a ~17.6 W ladder. Finer is meaningless</td></tr>

docs/field-guide.html

@@ -60,7 +60,7 @@ figcaption { font-size:9pt; color:#5b6169; margin-top:1.2mm; }
 <div class="page" id="p1">
   <div class="hdr">
     <div><h1>GoodWe RS485 Controller</h1>
-         <div class="sub">Field installation &amp; commissioning guide — v0.1.0</div></div>
+         <div class="sub">Field installation &amp; commissioning guide — v0.1.0, <b>outdated</b>: where it disagrees with DOCS.md, DOCS.md wins</div></div>
     <small>Installer copy</small>
   </div>
 
@@ -468,7 +468,7 @@ figcaption { font-size:9pt; color:#5b6169; margin-top:1.2mm; }
   <table>
     <tr><th style="width:30mm">Setting</th><th style="width:16mm">Value</th><th>Reason</th></tr>
     <tr><td><code>gain</code></td><td>0.6</td><td>Inverter needs 3–6 s to settle (1.4 s dead time, 94 % by 3.3 s) against a ~5 s cycle. <b>At the limit — do not raise</b></td></tr>
-    <tr><td><code>slew_w</code></td><td>1000</td><td>Most of a correction in the first cycle without running far ahead of the hardware</td></tr>
+    <tr><td><code>slew_w</code></td><td>0</td><td>0 follows the rail (<code>max_w</code>&nbsp;/&nbsp;9). A faster fixed value is <b>refused at startup</b> (SAFETY-39) — see DOCS.md</td></tr>
     <tr><td><code>deadband_w</code></td><td>15</td><td>Measured residual: mean 15.4 W, max 27 W. At 10 W the command never rests</td></tr>
     <tr><td><code>saturation_w</code> / <code>cycles</code></td><td>500 / 3</td><td>Divergence = inverter at a limit → magnitude may fall, never rise. <b>The 3-cycle term is essential</b>: tested instantly it fires on every large correction</td></tr>
     <tr><td><code>step_w</code></td><td>10</td><td>Register is 1 W but response lands on a ~17.6 W ladder. Finer is meaningless</td></tr>

goodwe_controller/DECISIONS/SAFETY-10-shadow-mode.md

@@ -0,0 +1,406 @@
+# SAFETY-10 — shadow mode, and why "default-on" is not `true`
+
+**Status:** decided and implemented on branch `SAFETY-10`.
+⚠️ **AMENDED BY SAFETY-47, and three of the claims below were false when this
+was merged.** §5's "the strategies are unaffected" exemption, §4's peak-guard
+row and §6's evidence table are corrected in place and each correction is
+marked. The amendments are marked rather than rewritten silently, because what
+this card believed is part of why the defect shipped. See
+`DECISIONS/SAFETY-47-what-a-shadow-run-can-show.md`.
+**Card:** SAFETY-10 — *"Shadow mode (default-on, log-only decisions)"*.
+**Nothing here reached the inverter.** No deployment, no `ha addons update`, no
+contact with 192.168.2.158 or 192.168.2.221. Everything below was measured in
+the CI image and on TEST-23 stage 3's closed-loop rig.
+
+---
+
+## 0. The four things a reader should take away
+
+1. **"Default-on" is delivered as `auto`, not as `true`, and the difference is
+   an install that is regulating a real battery today.** The Supervisor
+   composes an add-on's options as *its defaults, overlaid with the stored user
+   options*, so a new key with a new default reaches **every existing install**
+   on the next update. A boolean `shadow_mode: true` would silently stop the
+   reference site. §1.
+2. **Shadow mode WRITES. It writes 0 W, on the ordinary heartbeat, through the
+   ordinary single writer.** "Commands nothing" implemented as "stops writing"
+   would leave the inverter latched on whatever was standing — it has no meter
+   timeout — and would put the ESP32 into a tripped stale-input watchdog for
+   the whole run. §2.
+3. **The sign watchdogs are inert, and that was the decision that had to be got
+   right.** Fed the shadow decision they would trip within `sign_disagree_s`
+   and **latch a trip that survives into live operation and a restart**. §4.
+4. **The loop leg's shadow decision is one slew step, not a trajectory, and
+   that is a real limitation of this feature.** §5.
+5. ⚠️ **SAFETY-47: and neither is anything else that depends on the plant
+   answering back. A shadow run cannot surface a closed-loop defect at all**,
+   by the same construction that makes it safe — the battery is held at 0 W, so
+   every measured input describes a plant that did not respond. Of the three
+   defects §"WHAT DEFECT THIS PREVENTS" was written for, exactly one —
+   TARIFF-14's wrong quarter-hour — is visible from a shadow run. §5, §6.
+
+---
+
+## 1. The default
+
+### The literal reading, and what it costs
+
+`config.yaml`'s `options:` block **is** the default. There is exactly one of it,
+and HA's Supervisor resolves an add-on's effective options as
+
+```
+{**config.yaml options, **the stored user options}
+```
+
+A key that has never been stored therefore takes the file's value — on a fresh
+install and on an install that has been running for months, identically. There
+is **no mechanism in the add-on options system** by which one key can default
+differently for the two. So the card's title, taken at face value, is:
+
+> the next `ha addons update` stops the battery at the reference site, and the
+> only symptom is a battery that has stopped doing anything.
+
+That is strictly worse than every defect shadow mode exists to catch. It is
+refused.
+
+### What was shipped instead
+
+`shadow_mode` is a three-valued `list(auto|on|off)` defaulting to `"auto"`:
+
+| value | resolves to |
+|---|---|
+| `off` | live |
+| `on` | shadow, always |
+| `auto` | shadow **while control is stopped**; live once it is started |
+
+`auto` reads `Controller.auto` — the persisted start/stop state, which a fresh
+install takes from `auto_start` and which the *Start / stop control* button
+moves. No new persisted state, no migration, no guess:
+
+* a **fresh** install ships `auto_start: false`, has no stored `auto` key, and
+  therefore comes up **in shadow mode**. It observes a day of decisions before
+  it is ever allowed to command anything. That is the card's intent, delivered
+  where it is safe;
+* an install that is **controlling** is started, so `auto` resolves to live and
+  **not one watt changes**;
+* an install that is **stopped** keeps its actuator at 0 W exactly as before —
+  the same number, from the same writer, on the same heartbeat. What changes is
+  what the status page and the action log **say**, and that the decision path
+  now runs and is recorded.
+
+⚠️ **Under `auto`, pressing Start leaves shadow mode.** That is the point of
+`auto`: the button means "control the battery". An operator who wants the
+decisions recorded *while the loop runs* — the configuration this card exists
+to make possible — sets `on` explicitly, and cannot reach it by accident.
+
+⚠️ **An unrecognised value resolves to SHADOW, and is REFUSED at startup.**
+`shadow.mode()` fails toward inaction; `validate.py` rule 11 refuses the value
+by name so the reinterpretation is never silent. A typo is not a decision, and
+an install silently left in shadow mode commands nothing indefinitely while its
+status page calmly explains that this is intentional.
+
+---
+
+## 2. "Commands nothing" is a number, not a silence
+
+The inverter holds its last command **forever** — `HANDOVER.md` §6 says so, and
+`firmware/goodwe-master.yaml`'s header records what it cost when a controller
+stopped refreshing: *"Illusmart went silent mid-command and the inverter held
++5000 W for 113 s"*. `firmware/goodwe-master.yaml` states the contract that follows — *"HA
+must now REWRITE the setpoint every ~10 s even when the value has not
+changed"* — because without a refresh, **"stale" and "steady" are the same
+thing on the wire**.
+
+So shadow mode holds the actuator at `shadow.WIRE_W` = **0.0 W**, refreshed on
+the ordinary heartbeat. Two consequences were weighed and are recorded:
+
+* **it is not silence.** A shadow mode that stopped writing would leave the
+  standing command up until the ESP32's 30 s watchdog noticed — and at a site
+  with no such board, forever;
+* **it does not use an alarm as a mode.** Letting that watchdog trip for the
+  duration of a shadow run teaches the operator that `wd_tripped` is normal,
+  which is exactly the training that makes it useless when the add-on has
+  actually died.
+
+### It is not a second writer
+
+SAFETY-28's rule is one actuator, one writer. Shadow mode files **no claim**,
+owns **no transport**, and calls nothing in `hass.py`. It is a **substitution**
+inside `Controller._write_unit()` — the single choke point every write in this
+add-on already reaches, including the heartbeat, the stop button, `shutdown()`
+and `maint_abort()` — in exactly the form of the three substitutions above it
+(non-finite → 0 W, unauthorised → 0 W, clamped → the rating).
+
+It is the **last** of them. Below SAFETY-28's gate and below SAFETY-03's clamp,
+so both still grade the number the decision path actually produced, and a
+shadow run can report *"it would have hit the rating here"*.
+
+---
+
+## 3. What the run records
+
+| surface | what it carries |
+|---|---|
+| status banner | `SHADOW MODE - the battery is NOT being controlled...`, **first in the cascade**, amber — red, with the latch named, if one is standing |
+| status row `Shadow mode` | which rung decided, the watts it **would have commanded on this cycle**, where the inverter actually is, and `Resolution.explain()` — plus, when a measured billed quarter sized those watts, SAFETY-47's caveat saying so (`shadow.SIZED_FROM_METER`) |
+| status row `Commanded` | `0 W` — the truth, which the row above reconciles with the `Why` row below it |
+| action log | one line when shadow mode comes on; one line per **change of decision** (winner, rounded watts, or SAFETY-47's caveat state), carrying the arbiter's own sentence and the same caveat the row carries — `shadow.log_line()` is the one sentence both read |
+| MQTT | `status: shadow`, its own value, below `failsafe` |
+
+The action log is **edge**-logged, not level-logged: the log holds 40 rows, and
+a line per cycle would flush the context of the run's own findings inside four
+minutes at the 15 s cycle floor.
+
+---
+
+## 4. The failsafes, one by one
+
+| failsafe | in shadow mode | why |
+|---|---|---|
+| SAFETY-02/30 sign watchdogs | **INERT** | They grade `Inverter.standing_w()` — what this controller has standing on the wire — and shadow mode holds that at 0 W, so they cannot arm. ⚠️ Fed the shadow decision instead they would disagree with a meter that never saw it and **latch a trip that survives into live operation and a restart**: shadow mode would manufacture the failsafe it exists to help debug. ⚠️ **Two rungs hold it there** — `last_write` (the wire gate) and `inv.target` (the re-seed) — which is MUTATION.md's masking shape, so the mutation that reproduces the hazard defeats both as a pair (M6). Driven singly, dropping the re-seed does not reproduce it at all — measured |
+| SAFETY-03 clamp | **OBSERVES** | Runs on the decision, sets `clamp_last`, logs every engagement. Changes no command |
+| SAFETY-28 write gate | **OBSERVES** | Same placement, same reason: the question is who chose the number |
+| SAFETY-18 meter freeze | **OBSERVES**, unchanged | It takes no action live either; both halves of its conjunction are as true in shadow |
+| SAFETY-07/24/25 peak guard | **OBSERVES, AND SEES ONLY THE HOUSE** | Level-triggered, unlatched, files its claim as usual, so the recorded decision is the real one *for this meter*. ⚠️ **AMENDED BY SAFETY-47.** This row used to end "SAFETY-45's limit cycle is visible from a shadow run, which is the point". It is not: every term of `wanted = batt_w + excess` is measured, and in shadow mode the battery contributes nothing to either. Measured on the rig, same hour, same unsized code — **410 of 720 cycles engaged live, 0 of 720 in shadow** |
+| SAFETY-31 circulation | **OBSERVES AND MAY LATCH** | Its evidence is *measured* power. Packs pushing against each other while all are told 0 W is a real fault |
+| SAFETY-42 delivery | **OBSERVES AND MAY LATCH** | Same, against a share that is 0 W |
+| operator stop | **SUPPRESSED AS A CLAIM, ENFORCED AT THE WIRE** | The one deliberate change. Its `P_SAFETY` 0 W claim out-ranks everything, so leaving it in makes the recorded decision `"stopped"` on every cycle and the run answers the wrong question. The actuator ends at the same number either way, and the wire substitution is **strictly stronger**: a claim can be out-ranked, and it cannot |
+| inputs missing, non-finite, allocator refusal, arbiter contradiction | **UNCHANGED** | All resolve to 0 W, which is what the wire gets anyway |
+
+⚠️ **A latch that is already up stays up.** Nothing here clears one. The shadow
+banner **names** any standing latch and goes red for it, because a latch that is
+up while the controller is inert is up the moment it stops being inert.
+
+⚠️ **Maintenance is not in that table because shadow mode does not touch it.**
+The state machines are ticked on every cycle whether control is started or not,
+so a stopped install already runs them against a battery that does not move.
+Shadow mode inherits that, unchanged and unimproved. Recorded here rather than
+quietly fixed under another card's name.
+
+---
+
+## 5. The limitation, stated rather than discovered later
+
+`Controller._shadow_settle()` re-seeds the carried command (`self.target` and
+each `inv.target`) to `WIRE_W` at the **end** of every shadow cycle — after
+every in-cycle guard has read the decision. Three machines read that value as a
+statement about the **hardware**: the loop's `prev_w` and integrator,
+`standing_w()`, and SAFETY-42's share comparison. Re-seeded, they track reality,
+and **the exit is safe by construction** — the carried command already equals
+the standing one, so the first live cycle slews from 0 W like any other.
+
+⚠️ **The cost is real.** The loop's `prev_w` is therefore 0 W on every shadow
+cycle, so the loop leg's recorded decision is **one slew step from the standing
+command** and stays there. A shadow run answers *"what would this controller
+command NOW, from where the plant really is"* — a true statement about the
+present — and **not** *"what trajectory would it have followed"*. The trajectory
+is a closed-loop property, it did not happen, and reporting it would be a
+simulation of a plant that does not exist; three cycles in, such a number
+describes nothing.
+
+⚠️ **AMENDED BY SAFETY-47 — THE PARAGRAPH THAT STOOD HERE WAS THE DEFECT.**
+It read:
+
+> The strategies are unaffected: arbitrage, the peak guard and maintenance all
+> file `SET` claims at a fixed power from level-triggered inputs. That is why
+> the three defects this card was written for — SAFETY-45's 28 onsets an hour,
+> TARIFF-14's wrong quarter-hour, SAFETY-46's ceiling churn — are all visible
+> from a shadow run, and the loop's ramp is not.
+
+It was true until **SAFETY-45 merged, one commit before this card**. That
+change makes the buy leg `min(asked, headroom)` with
+
+```
+headroom = (900 / remaining) x (ceiling - projected)
+```
+
+and `projected` reads the **open quarter's accumulator** — the meter — which is
+a function of what the battery did earlier in that same quarter. The strategy
+is closed-loop, and the loop's one-slew-step limitation above is not a special
+case of anything: **it is the general case**, and the limitation is the whole
+feature's, not the loop leg's.
+
+**The correct statement, and it is now graded rather than asserted:**
+
+> A shadow run cannot surface a **closed-loop** defect — one whose stimulus is
+> the plant's response to the controller — because the battery is held at 0 W
+> and there is no response to be the stimulus. **Which** hour a strategy picks
+> and **why** are unaffected, because the clock and the price series are not
+> functions of the battery. **How hard** it trades is not.
+
+Of the three defects this card was written for:
+
+| | visible from a shadow run? | measured |
+|---|---|---|
+| SAFETY-45's limit cycle | **no** | 28 charge onsets live, **1** in shadow; grid −455.5 … +3200.0 W live, **flat at the 1200 W house** in shadow; guard engaged 410/720 live, **0/720** in shadow |
+| SAFETY-46's SoC churn | **no** | the SoC moves **0.000000000 pp** in a shadow run. No SoC limit can be *reached* in one |
+| TARIFF-14's wrong quarter-hour | **yes**, and it is the one | which hour, at what price, clearing what spread: identical live and shadow on **720 of 720** charging cycles, at a binding cap |
+
+Graded in `test_arbitrage.py` part **3d** — the same closed loop part 3c uses,
+run once live and once in shadow — and the loop leg's own limitation stays
+named in `test_watchdog.py` part 10 as `RECORDED LIMITATION`.
+
+---
+
+## 6. How "nothing reaches the inverter" is graded
+
+**Not on a flag.** A check that asserted `Controller.shadow` would pass on a
+build in which the flag is set and the substitution is deleted — which is
+exactly mutation **M1**.
+
+`test_clamp.py` part 8 drives the **shipped** `Controller.cycle()` and the
+shipped heartbeat against a recording Home Assistant stub, and asserts on what
+reached `set_number()`:
+
+* **the precondition first** — the same stimulus with `shadow_mode: off` puts
+  30 non-zero writes on the wire, the largest 5000 W. MUTATION.md habit 4: a
+  check whose data cannot reach the failure it names is decoration;
+* then `set(writes) == {0.0}`, **and** that there were 26 of them — a check
+  that only said "no non-zero write" would pass on the silent build too;
+* entry and exit are measured on `inv.last_write` — what the inverter is
+  latched on, updated only on an **accepted** write — either side of the
+  boundary, against the same run that never entered shadow mode.
+
+The closed-loop half is `/home/homelab/s10-mut/shadowloop.py` on TEST-23 stage
+3's rig: the same hour, twice, against `plantsim.Plant` through the firmware's
+own frame encoder.
+
+⚠️ **SUPERSEDED BY SAFETY-47 — THE TABLE THAT STOOD HERE COULD NEVER HAVE GONE
+RED, FOR TWO INDEPENDENT REASONS.** It read `arb_power_w` −2000 W *"identical"*,
+`arb_reason` *"identical, verbatim"*, arbiter winner *"identical"*, and
+concluded *"the decision happened, at the same instant, for the same reason, at
+the same signed power — and the battery did not move."* The battery half is
+true and is unchanged. The **decision** half was decoration:
+
+1. **the fixture is `peak_cap_w: 15000` against a 350 W house**, so the
+   capacity guard never engages and SAFETY-45's sizing is in the run and inert.
+   The harness's own comment says so — *"at this scenario's `peak_cap_w: 15000`
+   it is not binding anyway"* — which is MUTATION.md habit 4 written down
+   beside the check it disables;
+2. **every identity row reads the FIRST charging sample.** At `elapsed = 0`
+   the projection *is* the held level, so the two runs agree to the float there
+   **even at a cap that does bind**. Measured: closing reason (1) alone leaves
+   that comparison passing.
+
+Both had to be closed. Re-taken below at **`peak_cap_w` 1500 / house 1200 /
+`max_w` 2000**, one hour at a 5 s cycle, **across the whole run** — harness
+`/home/homelab/s47-mut/shadowloop47.py`, same rig, same three transcribed
+lines.
+
+| | live | shadow |
+|---|---|---|
+| grid | 1224.1 … 1506.0 W — **held up at the ceiling** | **1200.0 W flat = the house, exactly** |
+| SoC | 50.000019 → **51.856789 %** | 50.000000 → **50.000000 %** |
+| `ARBITRAGE_CHARGE` cycles | 720 / 720 | **720 / 720** |
+| first charging cycle, `arb_power_w` | −300.0000 W | **identical — and this is why the old table passed** |
+| `arb_power_w`, **whole run** | −307.799 … −299.930 W | **−2000.000 … −300.000 W** |
+| …cycles where the two differ | — | **716 of 720** |
+| `arb_reason`, whole run | the strategy's own sentence | **differs on 719 of 720** |
+| measured charging headroom | 299.93 … 307.80 W | **300.0 … 54 000.0 W** |
+| final recorded command | **−302.4 W** | **−2000.0 W — 6.61× the live figure** |
+| price / spread / which hour | | **identical on 720 of 720** |
+| arbiter winner | `arbitrage` | **identical** |
+
+**What the re-taken table says.** The decision still *happens*, at the same
+instant, on the same hour, at the same price, for the same *kind* of reason,
+and the battery still does not move — those were the card's real claims and
+they hold. What does **not** hold is that the decision is the *same decision*:
+its **size** is a function of a meter the battery never moved, and at this cap
+the recorded figure is 6.61× what a live controller commands. 54 000 W of
+"headroom" under a 1500 W ceiling is `900/remaining` multiplying a gap the
+battery never closed.
+
+⚠️ **And the SoC row is the second half of it.** 0.000000000 pp of movement is
+not a curiosity: it is the proof that **no SoC-limit behaviour is reachable
+from a shadow run at all**, which §5 used to promise.
+
+SAFETY-47 puts the caveat on both surfaces that carry the number and narrows
+the three documents' claims; `test_arbitrage.py` part 3d is the CI-side grader
+so this class cannot recur.
+
+⚠️ **Three lines of each harness are a TRANSCRIPTION and are marked as one.**
+`priceloop.Rig` has no `_write_unit()`, no clamp and no failsafe machine
+(divergence 2 of its README), so the substitution's **placement** is
+transcribed there. The shipped placement is graded by `test_clamp.py` part 8,
+which drives the real `Controller`. ⚠️ **And the rig's transcribed cycle
+predates SAFETY-45**: `arbitrage.decide()` gained a required
+`charge_headroom_w` after `478ba93`, and the harness supplies it from the
+**shipped** `peakguard.charge_headroom_w()` reading the **shipped** peak
+decision rather than from a constant, so SAFETY-45 stays in the run.
+
+---
+
+## 7. The mutation battery — 22 mutations, no survivors
+
+Harness: `/home/homelab/s10-mut/run.py`, backups beside it. Each run restores
+from backup, purges `__pycache__` **on the host**, and grades through the CI
+image with the tree bind-mounted `:ro`, so the interpreter cannot write a cache
+into the tree under test (TEST-15). The full table is in the branch report;
+one per new behaviour, including **M1** (the substitution deleted — a write
+escapes), **M2** (it returns instead of substituting — the inverter is left
+latched), **M3** (it moves above SAFETY-28 and SAFETY-03 — the observers go
+blind), **M8** (`auto` resolves to shadow unconditionally — the literal
+default-on that stops the live install), **M12** (the stop claim is filed in
+shadow — every recorded decision reads `stopped`), **M21** (the substitution
+and the re-seed together) and **M22** (the re-seed moved one line earlier —
+SAFETY-18 grades a 0 W no decision produced and goes permanently blind).
+
+⚠️ **Two findings from driving it, both of the kind MUTATION.md says to expect.**
+
+* **M2 first came back a SURVIVOR and was not one.** The "stop writing
+  altogether" build left `inv.last_write` as `None`, the check did `float()` on
+  it, and the section died with a `TypeError` — grading none of the checks
+  after it and reporting **zero reds**, which reads exactly like a survivor.
+  That is FCST-06's shape. The fixture now hands `None` back and names it as
+  its own check; M2 is red on three.
+* **M6 had to become a PAIR, and only the battery said so.** `standing_w()`
+  prefers `last_write` — the 0.0 W the wire gate accepted — and falls back to
+  `inv.target`, which the re-seed also holds at 0.0. Either rung alone keeps
+  the detector inert, so dropping the re-seed **singly** came back red on the
+  limitation check and on **nothing about the latch**: the hazard it names was
+  not reproduced. TEST-16's rule with a new name on it.
+* **M7/M8/M9/M19 had to MOVE SUITES.** They defeat `shadow.engaged()`, and a
+  defeated default stops `test_clamp.py` part 3's wired run reaching the wire
+  at all — aborting the file with an `IndexError` before part 8 is graded. The
+  red count there was a lower bound naming the saturation freeze. The mode
+  table now lives in `test_validate.py`, which drives no Controller.
+* **`shadow_would_w = float(self.target)` is an EQUIVALENT mutation and was
+  measured as one.** `_shadow_settle()` runs before the re-seed, so at that
+  line `self.target` **is** `resolution.target_w`. It is recorded as equivalent
+  rather than reported as a survivor, and the non-equivalent form of the same
+  defect — the record becoming the **wire** — is driven instead.
+
+### The table
+
+Each row: the mutation, the file, the byte delta, the suite it was graded in,
+and how many **named** checks went red. `⚠️` marks a row whose run did not
+reach the end of its file, so its count is a **lower bound** (MUTATION.md).
+
+| # | mutation | file | Δ | suite | reds |
+|---|---|---|---|---|---|
+| M1 | **a write escapes** — the substitution deleted | `main.py` | −6 B | clamp | 5 |
+| M2 | **silence instead of 0 W** — it returns rather than substituting | `main.py` | −15 B | clamp | 3 |
+| M3 | **the observers go blind** — it moves above SAFETY-28 and SAFETY-03 | `main.py` | +58 B | clamp | 1 |
+| M4 | the site re-seed dropped — the exit resumes from a fiction | `main.py` | −36 B | clamp | 3 |
+| M5 | the per-unit re-seed dropped | `main.py` | −22 B | clamp | 1 |
+| M6 | **PAIRED**: `standing_w()` reads the target **and** the re-seed dropped — the sign latch that survives into live operation | `inverter.py` + `main.py` | −170 B | watchdog | 3 |
+| M7 | `auto` inverted — shadow while started, live while stopped | `shadow.py` | +2 B | validate | 4 |
+| M8 | **default-on for everyone** — `auto` always shadow; the literal reading that stops the live install | `shadow.py` | −15 B | validate | 2 |
+| M9 | an unreadable value resolves to LIVE instead of shadow | `shadow.py` | +1 B | validate | 1 |
+| M10 | `validate.py` stops refusing an unknown value | `shadow.py` | −9 B | validate | 9 |
+| M11 | the loop leg gated on `auto` alone again — the decision path stops running | `main.py` | −17 B | clamp | 1 |
+| M12 | the stop claim filed in shadow — every decision reads `stopped` | `main.py` | −20 B | clamp | 1 |
+| M13 | the banner goes green while nothing is commanded | `shadow.py` | −2 B | clamp | 1 |
+| M14 | the banner loses the standing latch | `shadow.py` | −2 B | clamp | 1 |
+| M15 | the row renders the standing command instead of the decision | `shadow.py` | −8 B | clamp | 1 |
+| M16 ⚠️ | the row disappears when live | `main.py` | +43 B | clamp | 1 |
+| M17 | the record becomes the wire | `main.py` | −6 B | clamp | 7 |
+| M18 | level-logged — the 40-row action log floods | `main.py` | −23 B | clamp | 1 |
+| M19 | the two rungs render identically (masking) | `shadow.py` | +22 B | validate | 1 |
+| M20 | the shipped default moves to `off` in `config.yaml` alone | `config.yaml` | −1 B | defaults_pin | 1 |
+| M21 | **PAIRED**: the substitution **and** the re-seed deleted together | `main.py` | −103 B | clamp | 10 |
+| M22 | the re-seed moved one line earlier — SAFETY-18 grades a 0 W no decision produced and goes permanently blind | `main.py` | +40 B | clamp | 1 |
+
+**Survivors: none.** ⚠️ **M17's `+0 B`-adjacent sibling** —
+`shadow_would_w = float(self.target)` — is recorded in §7 as **equivalent**
+rather than counted here.

goodwe_controller/DECISIONS/SAFETY-39-slew-against-the-rail.md

@@ -187,6 +187,23 @@ over-absorption. So the rig does not choose the number — **the constraint
 chooses it, and the rig says what the constraint does and does not buy.** That
 is the same relationship the 2026-08-22 table had to its own three columns.
 
+⚠️ **FORWARD REFERENCE, ADDED BY SAFETY-48 — THIS TABLE AND THIS SENTENCE ARE
+TRUE OF release/1.0's LAW AND FALSE OF THE ONE THAT REPLACED IT.** Nothing above
+is retracted: re-run on release/1.0 today the same rig prints the same column
+(958 / 1107 / 1133 / 1058 / 987 / 1029 / 1150 / 1143 / 1081 W), flat,
+non-monotone, 800 better than 556. Under SAFETY-48's lead cap the **same script
+on the same plant** prints 777 / 734 / 663 / 563 / 553 / 507 / 435 / 358 / 321 W
+— falling monotonically, so a slower slew is now *better* and the sentence above
+inverts. The mechanism SAFETY-39 identified is exactly why: `slew_w` bounds the
+OUTPUT while the integrator goes on accumulating `gain · error`, so slowing the
+slew used to buy nothing; bound the integrator's lead and it starts to.
+`tools/slew_sim.py --slew` now names which of the two laws it is running under
+before it narrates the column, and
+`DECISIONS/SAFETY-48-bounding-the-integrator-lead.md` §6 carries both tables and
+the independent confirmation from `test_control.py`'s own plant model. ⚠️ **This
+does NOT re-open the choice of 556**: the constraint picks the number, the rig
+does not, and that is unchanged in both laws.
+
 ⚠️ **A single step is not evidence here.** The deadband, the 10 W quantisation
 and the phase of the step against the tick move the result by hundreds of watts,
 non-monotonically. The first cut of this derivation was a single step and ranked

goodwe_controller/DECISIONS/SAFETY-40-the-integrator-bound-is-not-a-bug.md

@@ -0,0 +1,28 @@
+# SAFETY-40: the integrator bound is not a bug
+
+**Decision.** `i_clamped` (the integrator reaching `integrator_max_w`, i.e.
+anti-windup) keeps alarming through the same `ClampWatchdog`: it is counted,
+notified on the same cadence, and escalates on a sustained run
+(SAFETY-41). It gets its own text, a `WARNING` and an amber status row. Only
+`clamped` (a command over `max_w`) and write-path clamps keep the BUG SIGNAL,
+the `ERROR` and the red row.
+
+**Why it still notifies.** On a default install `clamped` is unreachable
+(`control.py`, at the integrator bound), so the integrator bound is the only
+loop-side signal of a runaway such as the 14 768 W one. Silencing it would
+remove that. The card says the same: "the fix is to say the true thing, not to
+say less."
+
+**Why a bug has its own budget.** A genuine over-rating must not wait up to
+`REASSERT_S` behind anti-windup notices. `ClampWatchdog` tracks a separate
+`last_bug_alarm`, and a bug's text is never overwritten by later anti-windup
+text within an episode. Across episodes the WARNING uses its own
+notification id (`goodwe_integrator_bound`), so it cannot replace a BUG SIGNAL
+notice still on screen (review of #130). With only bug engagements, the cadence is the same as
+before (`test_clamp.py` part 9).
+
+**Numbers.** They come from the `Decision` of the clamping tick (`i_bound_w`,
+`requested_w`, `clamped_w`, `target_w`), not from `i_w` or `self.target`.
+
+**Open for the owner.** Whether scattered one-cycle anti-windup episodes should
+notify at all, or only log and count. They notify now, as before.

goodwe_controller/DECISIONS/SAFETY-45-sizing-the-trade.md

@@ -0,0 +1,221 @@
+# SAFETY-45 — the trade is SIZED by the capacity guard, not switched by it
+
+**Status: closed.** `peakguard.charge_headroom_w()` publishes the watts the open
+billed quarter can still afford; `arbitrage.decide()` takes it as a required
+keyword-only argument and sizes the BUY leg to it; `main.py` passes the measured
+guard's own number at its one call site. `peakguard.decide()` is **not changed** —
+byte-identical to `release/1.0` at `478ba93`, `sha256(decide) = 200090d0835a3a55`,
+7252 B on both trees.
+
+⚠️ **THE HOUSE LOAD IN EVERY FIGURE BELOW IS SYNTHETIC.** TEST-23 stage 3's
+`priceloop.py` drives a flat modelled house against a modelled pack
+(`plantsim.Plant`, 800 W/s ramp into a 10 s lag, 15 360 Wh). The PRICES are real,
+the decision code is the shipped code, the billed-quarter accumulator is
+`app/p1.py`'s own — the load is not. Nothing here is a measurement of the live
+site at 192.168.2.158, which this work did not touch.
+
+## 0. The defect, measured
+
+TEST-23 stage 3 found a sustained limit cycle with arbitrage armed and a charge
+decision active. Re-measured here on the same rig against the same checkout,
+metrics recomputed rather than copied — a **charge onset** is a cycle at which
+`arbitrage.decide()` transitions into `ARBITRAGE_CHARGE`, which is the edge the
+rig already logs:
+
+| `peak_cap_w` | house | onsets/h | mean period | grid swing | billed quarters (W) |
+|---|---|---|---|---|---|
+| 1500 | 1200 W | **28** | 131.1 s | **−455.5 … +3200.0 W** | 1490.1 / 1496.5 / **1508.8** |
+| 3500 *(shipped)* | 1800 W | 8 | 509.3 s | +127.5 … +3800.0 W | **3511.3 / 3536.0 / 3559.1** |
+| 3500 *(shipped)* | 3000 W | 32 | 114.8 s | +1202.0 … +5000.0 W | **3518.9 / 3542.2 / 3556.7** |
+| 5000 | 1200 W | 1 | — | +1240.6 … +3200.0 W | 3169.5 / 3200.0 / 3200.0 |
+
+The last row is the **negative control**: `load + max_w = 3200 W` never reaches
+the cap, so there is no cycle to remove. The bite rule is `load + max_w >
+peak_cap_w`, which at the shipped `peak_cap_w: 3500` / `max_w: 2000` is any house
+drawing over 1500 W in the cheapest quarter.
+
+§10.1's ordering did win on the money — the guard kept the quarters within tens
+of watts of the cap — but **every billed quarter in the three biting rows
+finished OVER it**, which is the thing §9.1 bills. §10.2: *"an EMS that
+oscillates is worse than no EMS, both for hardware wear and — per §9.1 — for the
+peak it is trying to avoid."*
+
+## 1. ⚠️ The mechanism is NOT mainly the quarter boundary, and the card says it is
+
+The card, and `.cache/s45.md` before it, describe the loop as *"at each quarter
+boundary the projection resets to 0, the guard disengages, and arbitrage re-arms
+at full power."* **That is not what the 28 onsets are.** Their timestamps, off
+the run above:
+
+    1, 231, 351, 471, 581, 696, 806, 896, 1136, 1256, 1371, 1486, 1596,
+    1711, 1811, 2061, 2176, 2296, 2411, 2521, 2626, 2716, 2971, 3091,
+    3206, 3321, 3431, 3541      (s, quarter boundaries at 900/1800/2700)
+
+**23 of the 27 gaps are 90–120 s, mean 111.5 s, entirely inside one quarter.**
+The four long gaps — 230, 240, 250, 255 s — are precisely the four that SPAN a
+boundary, so the boundary **lengthens** the interval rather than causing an
+onset. Only three onsets land within 15 s of a boundary and one of those is
+`t = 1`, the start of the run.
+
+The real cycle, read off the recorded fields at t = 1000…1180 s:
+
+1. the trade charges at `−2000 W`; the meter sits at 3200 W against a 1500 W
+   ceiling; `wanted = batt_w + excess` is **negative** (−132 → −8 W), so
+   `decide()` files **nothing** and arbitrage is not constrained at all;
+2. `wanted` drifts up as the quarter's own history worsens and the `900 /
+   remaining` gain grows, and crosses zero at t = 1055 with **`floor_w = 5.3 W`**;
+3. that 5 W floor flips `arbitrage.guard_state()` to `True`, which refuses the
+   **whole trade** — so the setpoint goes from −2000 W to +5 W and the
+   grid-following loop, which targets grid = 0 and not grid = ceiling, takes the
+   actuator and discharges to **+1870 W**, exporting 420 W;
+4. the projection collapses, `wanted` goes negative, the guard releases, and
+   arbitrage re-arms at **`max_w`**. 115 s later, again.
+
+So the defect is **a binary interlock keyed on a continuous quantity**, and the
+quarter boundary is one of the ways it is crossed rather than the cause. The
+card's other claim — *"projection 3092 W against a 1509 W ceiling, `engaged=False`,
+for 170 consecutive seconds"* — reproduces, but it is the **first** such window
+(`first_engaged_t_s = 151.0`); the steady-state silent window is ~40–65 s.
+
+None of this changes what the fix has to do. It is recorded because a card that
+says "the boundary is the trigger" invites a fix in the boundary handling, and
+such a fix would have removed four of twenty-eight onsets.
+
+## 2. What was rejected, and why
+
+### 2a. Reverting `decide()`'s `wanted <= 0.0` rung — rejected, and it is a trap
+That rung is 2026-08-20's anti-bang-bang. Its own comment records the cost of not
+having it: 17 engage/release cycles in 900 s and a quarter finishing 49 W over
+the limit it had spent a quarter of an hour holding. It is untouched, pinned on
+the AST in `test_peakguard.py` 13g, and `tools/replay_ac3.py` reproduces the same
+190/190, 110 engaged cycles, 5 blind, 878 Wh on this branch as on `478ba93`.
+
+### 2b. Filing the affordable charge as a NEGATIVE `lo` — rejected
+Arithmetically this is the prettiest answer: `lo = wanted` with no sign gate is
+continuous, is exactly the control law `decide()` already computes, and would
+have put the constraint on the arbiter where it binds every claimant rather than
+only arbitrage. It was rejected on two grounds, in this order:
+
+1. ⚠️ **IT CREATES A NEW `lo > hi` CONTRADICTION CLASS AGAINST THE MAINTENANCE
+   SHAPING.** `main.py`'s cheap-window maintenance charge files
+   `Claim.limit("maintenance", P_MAINT_SHAPE, hi=-floor)` — a NEGATIVE `hi`.
+   `arbiter.py` clause 2 applies every limit at or above the winner's priority
+   and takes the most restrictive, with **no notion of one limit out-ranking
+   another**; a peak `lo = −300 W` against a shaping `hi = −1000 W` is `lo > hi`,
+   which resolves to **0 W — the battery parked, in the one quarter of the month
+   that sets the bill**. That is the exact failure `peakguard.shaping_suspended()`
+   exists to prevent, and the only way to close it would be to key that
+   suppression on "a claim exists" — which, on every site this card is about,
+   means the maintenance charge-only shaping is suspended **permanently**. A
+   silent, large change to a different subsystem is not a price this card should
+   pay.
+2. It changes the meaning of `PeakDecision.engaged` at five call sites outside
+   this module — `arbitrage.guard_state()`, `shaping_suspended()`,
+   `claim()`, `main.py`'s edge-logged action line and `main.py`'s status row —
+   each of which today means "the guard is HOLDING" and would silently start
+   meaning "a claim exists".
+
+`test_peakguard.py` part 5's sweep asserts **no negative floor, ever**, and the
+reason it gives ("a `lo` limit is incapable of capping discharge or export only
+while it is non-negative") is, strictly, not the true reason — a `lo` of any sign
+caps neither. The invariant is still right and is still worth holding; §2b above
+is the argument that actually supports it, and it is recorded here rather than
+left for the next person to re-derive.
+
+### 2c. A backoff, cooldown or hysteresis constant in `arbitrage.py` — rejected
+The card asks whether the second half of the fix belongs in arbitrage: *"a trade
+refused at 14:59 and re-armed at 15:00 has learned nothing from the refusal."*
+It does belong there, but as a **size**, not as a memory. `arbitrage.py`'s
+hysteresis note is explicit that the switching decision is "which hour is it" and
+that **no timer is needed and none is invented**; `peakguard.py`'s design note
+spends a paragraph on why it carries no hysteresis constant. A cooldown would be
+a second control loop compensating for a limit the first one declined to file,
+and its constant would outlive whatever it was tuned against. The trade now
+re-arms at `ceiling − load` instead of at `max_w`, which is what "learning from
+the refusal" means when the refusal is a measurement.
+
+## 3. What was done, and the precedent it follows
+
+`control.maintenance_charge_floor()` has capped MAINTENANCE charging at *"the
+headroom left under the site's cap"* since the loop was written, and its
+docstring says why:
+
+> "A maintenance charge is the only thing this system does that is big enough and
+> long enough to set that peak, so it is capped by the headroom left under the
+> site's cap."
+
+⚠️ **THAT SENTENCE STOPPED BEING TRUE WHEN OPT-04 LANDED.** Price arbitrage is a
+second thing that is big enough and long enough — it commands `max_w` for a whole
+tariff interval, deliberately, against the meter — and it was given no such cap.
+This card gives it the same shape, with one difference that matters:
+`maintenance_charge_floor()` sizes itself from `peak_forecast_entity`, which is
+OPTIONAL and empty on a default install — the exact hole SAFETY-25 had to close
+in `shaping_suspended()`. `charge_headroom_w()` comes off `decide()`, which runs
+wherever P1 does.
+
+**The number is `wanted_w` read in the other direction.** `decide()` already
+computes `wanted = batt_w + excess` as the DISCHARGE that lands the quarter on the
+ceiling; a negative `wanted` is a permitted CHARGE of `−wanted`. No new
+arithmetic, no new constant.
+
+Two properties make it safe to hand a strategy, and both are swept rather than
+argued (`test_peakguard.py` part 13):
+
+* ⚠️ **IT IS INVARIANT IN THE BATTERY.** Raise the charge by dW and the meter
+  rises by dW, so `excess` rises by exactly dW while `batt_w` falls by dW:
+  `wanted` does not move. Measured across `batt_w` from −5000 W to +2000 W on one
+  banked quarter — the headroom is 1350.0 W at every one of the six points while
+  the `excess` those runs see moves through six distinct values. It is a
+  **feed-forward** number, so consuming it adds no feedback path around the plant.
+  The fixed point is `charge = ceiling − load`, with the meter ON the ceiling and
+  `wanted` parked a whole `ceiling − load` clear of the engagement boundary.
+* **HOLDING IMPLIES ZERO OR UNKNOWN.** Across 1080 swept combinations, not one
+  ENGAGED decision answers a positive headroom, so the function can never hand a
+  caller permission the guard's own `lo` is at that instant refusing.
+
+## 4. After, on the same rig, same command, same checkout
+
+| `peak_cap_w` | house | onsets/h | grid swing | energy bought | billed quarters (W) |
+|---|---|---|---|---|---|
+| 1500 | 1200 W | 28 → **1** | 3655.5 → **282.0 W** | 180.0 → **285.2 Wh** | **1500.0 / 1500.0 / 1500.0** |
+| 3500 | 1800 W | 8 → **1** | 3672.5 → 1687.6 W | 1652.9 → 1616.1 Wh | **3500.0 / 3500.0 / 3500.0** |
+| 3500 | 3000 W | 32 → **1** | 3798.0 → **474.7 W** | 482.9 → 475.3 Wh | **3500.0 / 3500.0 / 3500.0** |
+| 5000 | 1200 W | 1 → 1 | **identical** | **identical** | **identical** |
+
+* **One onset** means the trade starts once and runs for the whole window. The
+  battery is trading 100 % of the hour where it used to trade 43 %, 92 % and 54 %.
+* **Every billed quarter lands exactly on the cap and none over it**, where every
+  quarter in the three biting rows used to finish over.
+* **The money.** At 1500/1200 the site buys **58 % MORE** energy, because a
+  continuous 300 W trade beats a 2000 W trade that is cancelled for 57 % of the
+  hour. At the two shipped-default rows it buys **2.2 % and 1.6 % less** — and in
+  exchange the worst quarter drops from 59 W over the cap to 0 W over it. The
+  capacity tariff bills the month's single worst quarter with no averaging and no
+  forgiveness (specs.md:583), so that is not a trade-off, it is the ordering
+  §10.1 asks for.
+* The remaining 1687.6 W at 3500/1800 is the opening **ramp**, not a cycle: the
+  pack goes from 0 to 1700 W of charge in about ten seconds and the meter with
+  it. One onset, no export, no reversal.
+* The last row is bit-identical before and after. **This card costs nothing on
+  the installs it is not about.**
+
+## 5. What this does NOT fix, with sizes
+
+* **TEST-23 finding 1 — the export overshoot at the END of a trade** (356–938 W,
+  ≈0.37 × `max_w`) is untouched and is a different card. It happens when the
+  cheap interval ends and the grid-following loop takes back an actuator that was
+  holding a charge; nothing here changes the handover.
+* **A house whose load ALONE exceeds the cap** (`load > peak_cap_w`) still puts
+  `wanted > 0`, still engages the guard, and still refuses the trade outright
+  through the interlock — correctly, since you cannot buy in a quarter you are
+  already over on. The loop then drives to grid = 0 rather than to grid =
+  ceiling, which is more discharge than the guard asked for. Not swept here: all
+  four (cap, load) pairs on the record have `load < cap`.
+* **`arbitrage.claim()` still files the SIZED number, but the ARBITER can clamp
+  it further** and the strategy is not told. The reason line names the guard's
+  headroom, not the arbiter's `bound_by`. Pre-existing; not widened.
+* **The container leg was not re-run.** `hadrive.py` needs `test23s3-addon`
+  started, and that container is deliberately stopped because it is a second
+  writer on the setpoint entity under measurement. The in-process rig's twelve
+  transcribed lines are pinned by `test_arbitrage.py` 3b's AST check on
+  `main.py`'s call site, which is the line this card adds to them.

goodwe_controller/DECISIONS/SAFETY-47-what-a-shadow-run-can-show.md

@@ -0,0 +1,319 @@
+# SAFETY-47 — what a shadow run can show, and what it cannot
+
+**Status:** decided and implemented on branch `SAFETY-47`.
+**Card:** SAFETY-47 — *"shadow mode's claims, and the number on the status
+row"*.
+**Nothing here reached the inverter.** No deployment, no `ha addons update`, no
+contact with 192.168.2.158 or 192.168.2.221. Everything below was measured in
+the CI image and on TEST-23 stage 3's closed-loop rig.
+
+⚠️ **This is not a write-path defect and nothing in the write path was
+touched.** SAFETY-10's substitution, re-seed, authorisation gate and clamp are
+unchanged. What was wrong is what three merged documents **say** a shadow run
+can show you, and a number on the status row that can be **6.61×** what a live
+controller would command.
+
+---
+
+## 0. The four things a reader should take away
+
+1. **Shadow mode cannot surface a closed-loop defect. Not partially — not at
+   all**, and by the same construction that makes it safe. §1.
+2. **The "strategies are unaffected" exemption was true until SAFETY-45 merged,
+   one commit before SAFETY-10.** Sizing the buy leg to the billed-quarter
+   headroom made the strategy closed-loop. §2.
+3. **The recorded watts are the right answer to a question nobody asked, and
+   they are CAVEATED rather than re-computed.** Re-computing would mean the
+   recorded decision was no longer the decision the shipped path reached, which
+   is the one thing shadow mode has to be able to say. §3 records what was
+   rejected.
+4. **SAFETY-10 §6's committed evidence could never have failed, for two
+   independent reasons, and closing either one alone closes nothing.** §4.
+
+---
+
+## 1. Why the answer is "not at all", and not "not very well"
+
+Shadow mode holds every actuator at `shadow.WIRE_W` and re-seeds the carried
+command to it at the end of each cycle. So every **measured** input — the
+meter, the billed-quarter accumulator behind it, the battery power, the state
+of charge — describes a plant that **did not respond**.
+
+A closed-loop defect is, by definition, one whose stimulus **is** the plant's
+response to the controller. No response, no stimulus, nothing to see. This is
+not an implementation gap:
+
+* feeding the guards a **simulated** plant instead is exactly what SAFETY-10 §4
+  refuses for the sign watchdogs, and the reason generalises — a controller
+  reacting to a plant that does not exist drifts further from reality every
+  tick, and three cycles in its numbers describe nothing;
+* and SAFETY-10 §5 already conceded the same fact for the grid-following loop
+  ("one slew step, not a trajectory"). That was never a property of the loop.
+  **It is the general case**, and the loop leg was simply where it had already
+  been noticed.
+
+**So the closed-loop answer comes from a closed-loop rig (TEST-23 stage 3) or
+from a live run. There is no third place, and saying that plainly is worth more
+than the three sentences it replaces.**
+
+### Measured, on the rig, at a cap that binds
+
+`peak_cap_w` 1500 / house 1200 / `max_w` 2000, one hour at a 5 s cycle. Of the
+three defects SAFETY-10 was written for:
+
+| | visible? | measured |
+|---|---|---|
+| SAFETY-45's limit cycle | **no** | 28 charge onsets live, **1** in shadow. Grid −455.5 … +3200.0 W live, **flat at the 1200 W house** in shadow. Guard engaged 410/720 cycles live, **0/720** in shadow. (Taken with SAFETY-45 reverted — that is the defect being looked for.) |
+| SAFETY-46's SoC churn | **no** | the SoC moves **0.000000000 pp** in a shadow run. The SoC is the pack's integral of what the pack was commanded, and it was commanded 0 W. No SoC limit can be *reached* in a shadow run at all |
+| TARIFF-14's wrong quarter-hour | **yes**, and it is the only one | the price lookup's inputs are the clock and the price series, neither a function of the battery. Which hour, at what price, clearing what spread: **identical live and shadow on 720 of 720 charging cycles, at a binding cap** |
+
+### What a shadow run genuinely is for
+
+*Which* strategy wins, on *which* hour, at *which* price, for *which* reason,
+against which limits — the wrong-quarter-hour class, a trade armed on a day it
+should not be, a refusal whose sentence names the wrong subsystem, a clamp that
+would have engaged, a standing failsafe latch. That is a real and useful set,
+and it is the set the documents now claim.
+
+---
+
+## 2. The exemption, and exactly how much of it survives
+
+All three documents carried a version of:
+
+> The **strategies** are unaffected — price arbitrage, the capacity guard and
+> maintenance all ask for a fixed power **from inputs that do not depend on
+> what the battery did**.
+
+**True before SAFETY-45, false after it.** SAFETY-45 makes the buy leg
+`min(asked, headroom)`, and
+
+```
+headroom = (900 / remaining) x (ceiling - projected)
+```
+
+where `projected` reads the **open quarter's accumulator** — the meter — which
+is a function of what the battery did earlier in that same quarter. SAFETY-45
+merged one commit before SAFETY-10, so the exemption was stale on the day it
+was written.
+
+**What survives, and it is now graded rather than asserted:**
+
+> **Which** hour a strategy picks, and **why**, are unaffected — the clock and
+> the price series are not functions of the battery.
+> **How hard** it trades is not.
+
+⚠️ **The peak guard is not in the surviving half either.** Every term of
+`wanted = batt_w + excess` is measured, so in a shadow run the guard engages
+only if the *house alone* would put the quarter over the ceiling. Its
+**ceiling** and its **reasons** are worth reading from a shadow run; its
+**engagements** are not evidence of anything.
+
+---
+
+## 3. The number on the status row — decided, and what was rejected
+
+At `peak_cap_w` 1500 under a 1200 W house the status row read **"WOULD HAVE
+COMMANDED −2 000 W"**. A live controller commands **−302.4 W**. Measured on the
+shipped build:
+
+| cap / house | live commanded | shadow recorded | over by |
+|---|---|---|---|
+| 1500 / 1200 | −302.4 W | **−2000.0 W** | **6.61×** |
+| 3500 / 3000 | −502.6 W | −2000.0 W | 3.98× |
+| 3500 / 2000 *(shipped cap)* | −1502.6 W | −2000.0 W | 1.33× |
+| 3500 / 1800 | −1702.6 W | −2000.0 W | 1.17× |
+| 15000 / 350 | −2000.0 W | −2000.0 W | 1.00× |
+
+⚠️ **The arithmetic is not wrong.** `900/remaining` is correct for a meter that
+is genuinely under the ceiling, and in a shadow run the meter genuinely *is*
+under it, because the battery is not charging. **The recorded number is the
+right answer to a question nobody asked** — and the last row of that table is
+the fixture SAFETY-10's own evidence was taken on, which is why nothing
+reported it.
+
+### What shipped
+
+1. **Unconditionally**, the row and the log line stop forecasting: the watts
+   are introduced as what would have been commanded **ON THIS CYCLE**. No
+   number a shadow run records is a prediction of a live run, so no state
+   should read like one.
+2. **Conditionally**, whenever a **measured** billed quarter sized the number
+   being recorded, both surfaces carry `shadow.SIZED_FROM_METER`:
+
+   > ⚠️ AND ITS SIZE CAME FROM THE BILLED-QUARTER METER, WHICH HAS ONLY THE
+   > HOUSE IN IT WHILE THE BATTERY IS HELD AT 0 W. A live run sizes the same
+   > trade against a meter the battery is moving, so this is an UPPER BOUND and
+   > not a prediction; how far under it a live run lands is a closed-loop
+   > question and a shadow run cannot answer it.
+
+⚠️ **"Upper bound", and not "smaller", and the difference was measured.**
+Charging only *adds* offtake, so a live `projected` is never below a shadow one
+and the headroom never above it — with **equality at the start of every
+quarter**, where `900/remaining` is 1.0 and neither plant has moved. Measured
+pairwise over 3600 charging cycles in five configurations: **0 cycles below,
+730 exactly equal.** A sentence reading "smaller" would have been false on
+every one of those 730, and the first draft of this card said "smaller".
+
+⚠️ **And it names no factor.** How far under the bound a live run lands is a
+property of the site. A number invented for the row would be a second helping
+of the defect the sentence exists to disclose.
+
+⚠️ **The predicate is NOT keyed on whether the trade was capped, and that is
+the trap this card nearly walked into.** `arbitrage`'s own sentence says *"SIZED
+BY THE CAPACITY-TARIFF GUARD"* only when the headroom came out **below** the
+ask — which in a shadow run is the **start** of the quarter, where the two runs
+still agree to the float. By the end, `900/remaining` has multiplied the
+headroom **past** the ask, the trade is **not** capped, the sentence is silent,
+and the recorded number is at its **most** wrong. A caveat keyed on it would be
+quietest exactly where it is needed loudest. `arbitrage.sized_from_meter()` is
+keyed on the headroom having been **measured**, so it fires on both.
+`test_arbitrage.py` part 3d-8 drives the inversion.
+
+### Rejected, and why
+
+* **Re-compute the number so it does not amplify** — e.g. record
+  `ceiling − projected` (gain 1.0) instead of the sized figure. It matches the
+  live answer almost exactly at this cap, and it is the **worst** of the
+  options. It would be a **shadow-only sizing**: the recorded decision would no
+  longer be the decision the shipped path reached, while the arbiter, the
+  clamp, SAFETY-28's gate, the action log and MQTT all ran on the real one. A
+  second copy of the sizing arithmetic living in the display layer is
+  MUTATION.md's transcribed-predicate defect on an operator-facing surface, and
+  it generalises to no other strategy. SAFETY-10's whole safety argument is
+  that shadow mode is a **substitution at the wire**, not a second controller;
+  this would have made it a second controller everywhere except the wire.
+* **Record nothing where the sizing depends on measured state.** Tempting —
+  "no number beats a number 6.61× out". Rejected on three counts: it blanks the
+  row exactly when arbitrage is trading, which is when a commissioning engineer
+  most wants it; the action log's edge key is the rounded watts, so blanking
+  them either floods or silences the log; and a surface that flickers between a
+  number and a dash is harder to read than a number with a standing caveat.
+  The narrow version of this — dropping the watts only — was the closest
+  runner-up.
+* **Record the unsized ask alongside the sized one.** It adds a number without
+  adding a warning. The unsized ask is `max_w`, a constant the operator
+  configured; on the shipped 3500/2000 row both figures are 2000 W, so the pair
+  is exactly as misleading as the single figure was.
+* **A caveat on every cycle in every state.** Rejected as the *whole* answer,
+  accepted as half of it: the unconditional part is a two-word narrowing of the
+  verb ("on this cycle"), not a warning, and the warning proper is conditional
+  so that it still means something when it appears.
+
+---
+
+## 4. SAFETY-10 §6's evidence, and why it could not fail
+
+§6 tabulated `arb_power_w` −2000 W *"identical"*, `arb_reason` *"identical,
+verbatim"*, arbiter winner *"identical"*. Two independent reasons it could
+never have gone red:
+
+1. **the fixture is `peak_cap_w: 15000` against a 350 W house**, so the guard
+   never engages and SAFETY-45's sizing is in the run and inert. ⚠️ **The
+   harness's own comment says so** — *"at this scenario's `peak_cap_w: 15000`
+   it is not binding anyway"* — which is MUTATION.md habit 4 written down
+   beside the check it disables;
+2. **every identity row reads the FIRST charging sample.** At `elapsed = 0` the
+   projection *is* the held level, so the two runs agree to the float there
+   **even at a cap that does bind**.
+
+⚠️ **AND THAT SECOND REASON IS THE ONE A REVIEWER CANNOT SEE FROM A DIFF.**
+Widening the fixture alone — the obvious fix — leaves the `[0]` comparison
+passing. Measured, not reasoned: at 1500/1200 the first charging cycle is
+−300.0000 W in **both** runs while 716 of the 720 cycles differ. Part 3d-2
+grades that agreement **as an expectation**, so nobody rebuilds a check on
+`[0]` believing it covers something.
+
+This is habit 4's **twelfth** instance in this repository, its **second**
+inside a committed evidence artifact, and — like the seventh and the eleventh —
+it was in a **measuring instrument** rather than in a check.
+
+§6 is re-taken at `peak_cap_w` 1500 / house 1200 / `max_w` 2000, across the
+whole run. Harness `/home/homelab/s47-mut/shadowloop47.py`.
+
+---
+
+## 5. The grader, so this class cannot recur
+
+`test_arbitrage.py` part **3d** — placed beside part 3c, which is SAFETY-45's
+own closed-loop regression, and built on the **same** `s45_loop()` harness so
+the two runs share every line of shipped code and differ in **one argument**:
+
+```
+s45_loop(sized=True)                  the live hour
+s45_loop(sized=True,  shadow=True)    the same hour, battery held at WIRE_W
+s45_loop(sized=False, shadow=True)    SAFETY-45's own defect, watched from
+                                      inside shadow mode
+```
+
+Three lines of `s45_loop()` stand in for `Controller._write_unit()`'s
+substitution and `_shadow_settle()`'s record and re-seed. They are marked as a
+**transcription**; `test_clamp.py` part 8 is the check on the shipped
+placement, and it drives the real `Controller`. Everything that produces a
+number — the averager, the projection, the guard, the headroom, the strategy,
+the arbiter, the row and the log sentence — is the shipped one.
+
+What 3d grades, in order: that the cap **binds** (the precondition the old
+evidence lacked); that the first charging cycle agrees **anyway**; that the
+whole run diverges, and by how much; that the record is an **upper bound**, and
+the two-point arithmetic that makes it one; what survives of the exemption;
+that SAFETY-45's limit cycle and the guard's engagements are **not** visible;
+the four rungs of `sized_from_meter()`, each reached with the other three clear
+(TEST-16); both operator surfaces; the `capped`-keying trap; and main.py's
+three call sites, pinned on the AST.
+
+⚠️ **The section carries its own precondition into every check.** A mutation
+that stops either run trading left the lists empty, the first `min()` raised,
+the file died before part 4 and the run reported **zero reds — which reads
+exactly like a survivor**. That is FCST-06's shape and it was **driven**, not
+imagined. `s47check()` now fails every check in the section when the stimulus
+was not produced, and the one division in it answers `nan` rather than raising.
+
+---
+
+## 6. The mutation battery — 14 mutations, no survivors
+
+Harness `/home/homelab/s47-mut/run.py`, backups inside it. Each run restores
+from backup, purges `__pycache__` **on the host**, and grades through the CI
+image with the tree bind-mounted `:ro`, so the interpreter cannot write a cache
+into the tree under test (TEST-15). Fingerprints are printed before the first
+run and re-checked after the last restore.
+
+| # | mutation | file | Δ | reds |
+|---|---|---|---|---|
+| M1 | the row drops the caveat branch | `shadow.py` | −63 B | 2 |
+| M2 | **the trap**: `sized_from_meter()` keyed on the trade being CAPPED — silent where the record is multiples out | `arbitrage.py` | +33 B | 5 |
+| M3 | the CHARGE rung dropped — a sell carries a caveat §9.1 makes false | `arbitrage.py` | −30 B | 1 |
+| M4 | the measured-headroom rung dropped | `arbitrage.py` | −18 B | 1 |
+| M5 | the arbiter-winner rung dropped — a caveat on somebody else's number | `arbitrage.py` | −33 B | 1 |
+| M6 | `main.py` renders the row with `sized_from_meter=False` | `main.py` | −23 B | 1 |
+| M7 | `main.py` drops `winner=` — the rung exists and is never reached | `main.py` | −1 B | 1 |
+| M8 | `main.py` sizes the trade from a literal — SAFETY-45 out of the shipped path, which the hoist put at risk | `main.py` | −41 B | 2 |
+| M9 | the headroom assignment moves out of `cycle()` | `main.py` | −39 B | 1 |
+| M10 | `sized_from_meter` gains a `False` default (TEST-14) | `shadow.py` | +8 B | 1 |
+| M11 | `ON THIS CYCLE` deleted — the row forecasts again | `shadow.py` | −14 B | 1 |
+| M12 | `log_line()` drops the caveat — the page discloses, the record does not | `shadow.py` | −63 B | 2 |
+| M13 ⚠️ | `main.py` re-assembles the log sentence at the call site | `main.py` | **+0 B** | 1 |
+| M14 ⚠️ | `wanted = batt_w − excess` — the headroom stops being monotone in the battery and the row's UPPER BOUND sentence becomes false | `peakguard.py` | **+0 B** | 38 |
+
+**Survivors: none.**
+
+⚠️ **M13 and M14 are `+0 B`, which MUTATION.md names as the risky delta.** Both
+were confirmed on disk by `sha256` before the run started — the harness prints
+the fingerprint of every graded file and the hash moved for each — and every
+run is purged, so neither is at risk of the stale-`.pyc` failure.
+
+⚠️ **Two findings from driving it, both reported rather than tidied away.**
+
+* **M14's first form was aimed at the wrong direction and correctly survived.**
+  `min` → `max` in the buy leg's sizing makes the shadow record *larger*, which
+  is still an upper bound, so 3d-3b was right not to fail. The mutation that
+  actually inverts the bound is the sign of the excess term in `wanted`. A
+  survivor that is right is worth more than a red aimed at the wrong claim.
+* **M12 was a survivor before the fix it forced.** Deleting the caveat from the
+  action-log line left **all 29 files green**: the only check that could see
+  that line drives a fixture with `meter_source: off`, where no arbitrage
+  decision — and therefore no caveat — is reachable. The sentence was an
+  f-string inside `Controller._shadow_settle()`, i.e. a surface no check could
+  grade. It is `shadow.log_line()` now, for the reason `words()` is a function,
+  and M13 is the mutation that puts it back at the call site.

goodwe_controller/DECISIONS/SAFETY-48-bounding-the-integrator-lead.md

@@ -0,0 +1,551 @@
+# SAFETY-48 — the slew step ceiling reaches the integrator, and what it bounds is the LEAD
+
+**Status:** decided and implemented on branch `SAFETY-48`, on top of `TEL-10`.
+**Card:** SAFETY-48 — *"the integrator goes on winding while the command is
+slew-limited"*.
+**Nothing here reached the inverter.** The live install still runs `slew_w: 400`
+applied by hand on 2026-09-05 12:00 and `release/1.0`'s control law. This branch
+does not deploy and does not bump the version.
+
+---
+
+## 0. The four things a reader should take away
+
+1. **It is a missing case, not a wrong constant, and the arithmetic says so.**
+   The integrator moves `gain * error` a cycle and the command moves at most
+   `slew_w`, so the integrator outruns the command whenever
+   `|error| > slew_w / gain` — 667 W at the live shape. SAFETY-39's retune made
+   `slew_w` **smaller**, which makes that threshold **lower**. §1.
+2. ⚠️ **THE FORM THE CARD ASKED FOR RAISES THE BILLED QUANTITY, AND THAT IS WHY
+   IT IS NOT WHAT SHIPPED.** Reusing the asymmetric freeze on a carried slew
+   flag cuts export 13 % and moves the worst quarter-hour average **offtake**
+   from 3739 W to **3935 W**, with the mean quarter +2.7 W — and on the billed
+   quarter it is worse at **every plant lag where release/1.0 produces a peak
+   at all** (a tie at lag 0, worse at 2.5 / 5.0 / 7.5 / 10.0 s) and at **every
+   top-N cut of the quarters**, which makes this the least lag-sensitive result
+   in the card. The harm is a tail redistribution inside quarters that already
+   net to offtake, not a weaker answer to import in aggregate. §3, §3a.
+3. **What ships bounds the LEAD at one slew step, only where the slew is what
+   stopped the command, and only in the leading direction.** The robust result
+   is the **export reduction — 39.6 → 34.1 kWh, and it falls at every plant and
+   tuning tried** — with wasted throughput 4.67 → 3.19 kWh, sign reversals
+   2992 → 2770 and median recovery 232 → 199 s. ⚠️ **The billed quarter is not
+   something this card can claim.** It reads 3739 → **3434 W** at the fitted
+   plant lag of 7.5 s; at every lag ≤ 5.0 s — including the one that best
+   reproduces the recorded export — release/1.0 is *already* at 3434 W and this
+   card moves it by exactly zero. The lag is not identified by the data. §4,
+   §3a.
+4. **Two committed numbers moved and neither is a silent edit.** SAFETY-13's
+   released command settles lower, because there is less wound integrator to
+   settle onto; and SAFETY-39's *"the slew does not own the over-absorption"* is
+   now **false — inverted, on its own independent plant model.** §5, §6.
+
+---
+
+## 1. The defect, in the terms the code uses
+
+`compute()` freezes the integrator with an asymmetric rule, and the comment
+beside it states the requirement outright:
+
+> the requirement is that the INTEGRATOR stop accumulating, not only the command
+
+But `frozen` is computed from **one** signal:
+
+```python
+saturated_now = abs(prev_w - actual_w) > tuning.saturation_w   # not tracking
+```
+
+Slew-limiting never enters it. When the command hits the step ceiling the
+integrator keeps winding at `gain * error` until it reaches `integrator_max_w`,
+and the unwind afterwards is `integrator_max_w / slew_w` cycles — 12.5 at the
+live shape, about a minute at the meter's measured tick.
+
+⚠️ **AND THE RETUNE MADE IT MORE FREQUENT, NOT LESS.** `|error| > slew_w / gain`
+is 1667 W at `slew_w: 1000` and **667 W** at `slew_w: 400`. The measured median
+grid error at the onset of a recorded episode is 1114 W — above the second
+threshold and below the first. This is why SAFETY-39 did not fix it, and the
+mechanism is the same one §6 shows inverting.
+
+## 2. How it was measured, and what the measurement cannot say
+
+`tools/replay_recorded_loop.py`, over **16.00 days / 256 252 meter instants** of
+the live install's own recorder, exported read-only.
+
+**Real:** the disturbance (`D = grid + batt` at every recorded meter instant —
+the house with this loop's own battery taken back out, which is exogenous and
+therefore valid to drive a counterfactual with); the tick (the meter's own
+recorded instants, median **5.01 s**); and the control law, imported out of the
+checkout. The "before" law is the **same file** with the SAFETY-48 block removed
+by a named substitution and exec'd into a fresh namespace — never a
+transcription — and a missing or duplicated anchor is a **refusal** with
+`NOTHING HAS BEEN MEASURED` on it, because an instrument that quietly compared
+the shipped law with itself would report the card as changing nothing.
+
+**Modelled:** the inverter (pure delay 7.5 s + first-order lag 2.0 s +
+`batt = 0.973 × cmd − 22.4 W`, fitted on this same recording above the SoC
+floor, residual **375 W RMS**); the pack (SoC integrated, discharge refused at
+or below the floor); and **everything else the arbiter does** — the recorded
+setpoint is the arbiter's output after the peak guard, the SoC clamps,
+maintenance and arbitrage, while the replay runs `compute()` alone.
+
+⚠️ **THE ABSOLUTE FIGURES ARE PESSIMISTIC BY ABOUT A THIRD AND THE TOOL PRINTS
+IT ON EVERY RUN.** Replaying the before-law reproduces 39.6 kWh of export where
+the install actually exported **29.4 kWh** over the same window. The delta is
+what this instrument is for: both laws run on the same ticks, the same
+disturbance, the same plant and the same seed.
+
+⚠️ **THE SoC FILTER ON THE PLANT FIT IS THE WHOLE FIT, AND IT IS A FINDING IN
+ITS OWN RIGHT.** This install spends **36 % of its ticks at or below a 10 % SoC
+with the command standing near 2 kW and the battery delivering nothing.** Fitted
+over all ticks the recording says `batt = 0.50 × cmd − 396 W, r = 0.70` — a
+plant that follows half the command, which no inverter does. Above the floor the
+same data says `batt = 1.00 × cmd − 28 W, r = 0.977`. The floor is the PACK and
+is modelled separately.
+
+## 3. The form the card asked for, and the number that refused it
+
+The card asked for the asymmetric rule already in service for saturation, on a
+flag carried across cycles the way `sat_count` is. It was built — from
+release/1.0's own source, one substitution per change — and measured on the same
+16 days through the same pipeline:
+
+| | release/1.0 | **form A** — carried slew flag + the asymmetric freeze | **SAFETY-48** — the lead cap |
+|---|---:|---:|---:|
+| export kWh | 39.61 | 34.43 | **34.07** |
+| import kWh | 116.07 | 110.62 | 111.20 |
+| battery sign reversals | 2992 | **2656** | 2770 |
+| wasted throughput kWh | 4.67 | **2.99** | 3.19 |
+| **worst 15-min offtake W** | 3739 | ⚠️ **3935** | **3434** |
+| mean quarter-hour offtake delta | — | ⚠️ **+2.73 W** | **−2.39 W** |
+| worst quarter-hour delta | — | +992 W | +532 W |
+| recovery median s | 232 | **184** | 199 |
+| recovery p99 s | 849 | **781** | 850 |
+| recovery max s | 901 | 890 | 898 |
+| unrecovered (> 900 s) | 53 | **26** | 31 |
+| \|i_w − prev_w\| p99 W | 3361 | 1534 | **800** |
+| \|i_w − prev_w\| max W | 9200 | 6912 | **800** |
+
+**Form A wins on four rows and loses on the one that is billed.** The capacity
+tariff (*capaciteitstarief*) bills the month's worst quarter-hour average
+offtake, and form A raises it by **196 W** — and raises the MEAN quarter by
+2.7 W, so this is systematic and not one unlucky quarter. It does so in **five
+of the six** plant and tuning variants in `--sensitivity`; the sixth is a tie.
+
+The per-cycle mechanism is that a frozen integrator stops at
+`prev + gain·error(first cycle)`, which is `(1 − gain)` short of what the site
+needs — 40 % short at `gain: 0.6`.
+
+⚠️ **AND THE SENTENCE THAT USED TO FOLLOW THAT ONE WAS TOO BIG FOR THE DATA.**
+It read *"for an IMPORT it is offtake, so a large import is answered too weakly
+for as long as the ramp lasts"*. The aggregate does not show a weaker answer to
+import: form A cuts total import by **5.45 kWh** and export by **5.18 kWh**
+against release/1.0, and paired tick by tick it delivers **8.56 kWh LESS**
+offtake energy on the ticks release/1.0 spent importing (lower on 38 229 such
+ticks, higher on 19 669). What form A moves is the **TAIL, within quarters that
+already net to offtake** — the worst quarter goes 3739 → 3935 W, the top five
+3260 → 3300 W, the top fifty 1880.0 → 1882.7 W. The capacity tariff bills the
+worst quarter and nothing else, so a redistribution that leaves the mean alone
+and lifts the maximum is exactly the trade that is refused here. The conclusion
+is unchanged; the causal sentence is now the one the data supports.
+
+⚠️ **THE CARD SAID "do not invent a second rule", AND THE MEASUREMENT SAYS TO.**
+That instruction is recorded here rather than quietly dropped. What ships is a
+different rule; the paragraph above is why.
+
+## 3a. ⚠️ The plant lag is NOT identified by this recording, and the billed quarter is the claim that depends on it
+
+`fit_plant()` picks `lag 7.5 s` because it minimises **battery-power RMS**. That
+objective barely distinguishes the candidates — 375.3 W at 7.5 s against 376.4 W
+at 2.5 s, **0.3 %** — while the tool's *own* printed fidelity measure, replayed
+export against the **29.43 kWh this install actually exported**, prefers 2.5 s by
+the whole of the 35 % gap the header warns about. Two measures on the same data
+disagree, and nothing here breaks the tie.
+
+So the sweep has to be read as a sensitivity, not as a confirmation:
+
+| plant lag | fit RMS W | replayed export kWh (release/1.0) | **worst 15-min offtake W:** release/1.0 | form A | SAFETY-48 | mean quarter ΔW |
+|---:|---:|---:|---:|---:|---:|---:|
+| 0.0 | 392.3 | 23.5 | **3434** | 3434 | **3434** | +0.53 |
+| 2.5 | **376.4** | **28.9** ← nearest 29.43 | **3434** | ⚠️ 3732 | **3434** | −0.59 |
+| 5.0 | 378.0 | 32.1 | **3434** | ⚠️ 3711 | **3434** | −1.02 |
+| 7.5 | **375.3** ← chosen | 39.6 | 3739 | ⚠️ 3935 | **3434** | −2.39 |
+| 10.0 | 384.2 | 75.4 | 3954 | ⚠️ 4326 | **3434** | −4.65 |
+
+(The RMS column is `fit_plant()`'s own inner sweep pinned to one lag — best `tau`
+and a re-fitted gain/offset at that lag. The export and quarter columns follow
+`--sensitivity`'s convention instead: only the lag is substituted into the
+global fit, everything else held. That is why the lag 5.0 and 10.0 export
+figures are the ones already printed in §7b.)
+
+⚠️ **AT EVERY LAG ≤ 5.0 s THE IMPROVEMENT IS NOT AN IMPROVEMENT — IT IS AN
+ABSENCE.** release/1.0's worst quarter is *already* 3434 W there and SAFETY-48
+changes it by **exactly zero**. §7b's paragraph used to read the `3434 → 3434`
+rows as "the direction does not move"; that is the wrong reading. The direction
+has nothing to move: at those plants release/1.0 never produces a quarter worse
+than 3434 W in the first place, and the 3739 → 3434 W headline exists only at
+the single longest lag `fit_plant()` happens to select. **The peak claim is a
+property of the plant model, not of the card.** What the card can claim on the
+billed quantity is that it does not make it worse, at any lag.
+
+⚠️ **AND THE ONE RESULT HERE THAT IS NOT LAG-SENSITIVE IS THE FORM-A
+REJECTION.** Form A's worst quarter is the worst of the three at **every lag
+where release/1.0 produces a peak at all** — 3732, 3711, 3935, 4326 against
+release/1.0's 3434, 3434, 3739, 3954 at lags 2.5 / 5.0 / 7.5 / 10.0, and a tie
+at lag 0.0 where both sit at 3434. It is worse at every top-N cut of the
+quarters at the fitted plant (top-1 3934.6 against 3738.7, top-5 3299.7 against
+3260.5, top-10 2890.6 against 2871.0, top-50 1882.7 against 1880.0, top-100
+1481.7 against 1479.0), and it raises the mean quarter. §3 understated this: the rejection does not rest on one unlucky
+quarter at one plant, which is exactly the objection a lag-sensitive result
+invites.
+
+⚠️ **WHAT WOULD SETTLE IT IS NOT IN THIS RECORDING.** Both objectives above are
+computed from the same four recorded entities, and they disagree; nothing else
+in the capture breaks the tie, and this card did not go looking for a third
+objective after seeing which lag each of the first two preferred. A driven step
+response — the command timestamped where it is written rather than where Home
+Assistant recorded it — is what identifies a lag. That is a rig measurement and
+it is not this card. Until it exists, the export reduction is what this card
+delivers and the peak figure is a plant-model artefact.
+
+## 4. What ships
+
+```python
+    slew = slew_limit_w(tuning)
+    slewed = max(prev_w - slew, min(prev_w + slew, target))
+    if slewed != target:
+        reason = "slew-limited"
+        _lead_cap = SLEW_LEAD_STEPS * slew
+        if target > slewed:
+            i_w = min(i_w, slewed + _lead_cap)
+        elif target < slewed:
+            i_w = max(i_w, slewed - _lead_cap)
+    target = slewed
+```
+
+Four properties, and each of them is a decision:
+
+* **It is inside the branch**, and ⚠️ **that placement was a SURVIVOR of all
+  thirty files until a check was written for it.** Applying it to every cycle
+  instead — `i_w = max(target - cap, min(target + cap, i_w))` after
+  `target = slewed`, −92 B — is **bit-identical on the shipped configuration**:
+  0 of 256 246 ticks differ over the 16-day recording. The two separate **only**
+  where `integrator_max_w` is set ABOVE `max_w` — the configuration `control.py`
+  says is the only way its `clamped` reason is reachable. There the integrator
+  is *deliberately* allowed above the rail, and an unconditional cap would drag
+  it back to the command every cycle and make the option inert.
+  `test_telemetry.py` part 4 drives that configuration, and the unconditional
+  form is red on it.
+
+  ⚠️ **THE COUNT OF SEPARABLE STATES IS DECORATION AND THREE SWEEPS DISAGREE
+  ABOUT IT.** This card's grid gave **2050 of 257 400**; an independent review
+  measured **1220 of 246 064**; a third, smaller grid (four tunings × 7 `prev_w`
+  × 9 `grid_w` × 5 `actual_w` × 8 `i_w` including `None` × 4 `sat_count`) gives
+  **776 of 40 320** — and that third one is spelled out here precisely because
+  the first two are not, which is the whole reason they cannot be reconciled.
+  No count here should be read as exact without the grid beside it. All three
+  agree on the load-bearing part, which is **where**: every separable state sits
+  in the `integrator_max_w > max_w` tuning and nowhere else.
+
+  ⚠️ **AND AN EARLIER DRAFT OF THIS BULLET GAVE THE WRONG REASON AND THE WRONG
+  NUMBER.** It said the two forms differ on 118 ticks because an unconditional
+  cap would pull the integrator toward a command the SATURATION freeze is
+  pinning. That 118 was measured against a *different* pair — a band applied
+  after quantisation, at the very end of `compute()` — and the saturation story
+  does not apply to the placement actually being compared, which sits before
+  the freeze. The figures above are the ones that were measured on the pair the
+  sentence names.
+
+  ⚠️ **AND THE SATURATION STORY IS NOT MERELY INAPPLICABLE — IT IS BACKWARDS.
+  THE NARROW CAP THAT SHIPPED *DOES* MOVE A SATURATION-FROZEN INTEGRATOR.** It
+  sits before the freeze block and is not gated on `frozen`. Measured on the
+  same 16 days at the live shape: of **79 160** frozen ticks the cap changed
+  `i_w` on **1095**, and on **679** of those it moved it further out on the side
+  it was already on — putting back magnitude the freeze had just let fall, which
+  is the one direction the freeze's rule ("may fall, never rise") exists to
+  forbid. Worst case **2424 W**, at
+  `prev_w −3400 W, grid +4697 W, actual −4144 W, sat_count 2 → 3`: the freeze
+  leaves the integrator at **−176 W**, the slew binds, and the cap drags it to
+  **−2600 W**. It never overrides a *same-cycle* refusal — the freeze clipped
+  `moved` on 75 512 ticks and the slew bound on none of them — but the claim
+  that this placement leaves the frozen path alone is false, and §5 is where
+  that shows up in a committed number.
+* **It is written one-sided, and that is a CLARITY choice, not a correctness
+  one.** ⚠️ **An earlier draft of this file and of the comment in `control.py`
+  said the two-sided band `max(slewed - cap, min(slewed + cap, i_w))` was a bug
+  that would drag a TRAILING integrator up toward the command. That was
+  invented, and the sweep said so: the two spellings agree on 205 920 of
+  205 920 cases** across four tunings, every sign of `prev_w`, `grid_w`,
+  `actual_w` and `i_w`, and the `i_w=None` path. `target` is monotone in `i_w`,
+  so when the slew binds `i_w` lies on the same side of `slewed` as `target`
+  does and the other clamp cannot reach. The one-sided form stays because it
+  NAMES the side the lead is on; the equivalence is recorded so the next reader
+  finds a measurement instead of an argument.
+* **It moves `i_w` and not `target`.** This cycle's command is already decided;
+  what is bounded is what gets CARRIED. That is also why the exhaustive
+  `i_w=None` equivalence sweep in `test_control.py` is untouched — it compares
+  `(target_w, sat_count, frozen, reason)`, none of which this moves.
+* **The cap is in STEPS, not watts**, for SAFETY-39's reason: a watt figure is a
+  constant that outlives the `slew_w` it was derived against. `SLEW_LEAD_STEPS`
+  moves with `slew_limit_w()` and therefore with the rail.
+
+⚠️ **ONE STEP, AND NOT ZERO.** `i_w = slewed` is full back-calculation, and
+`control.py`'s own docstring says what that costs: passing `i_w=None` *"reduces
+this function to the exact velocity form it replaced"*. A zero cap makes `i_w`
+identically the command on every cycle, which is that collapse written from the
+other end. Measured, it is **better** — export 32.02 kWh against 34.07, mean
+quarter −3.69 W against −2.39 — and it is still refused, because it throws away
+the reason the accumulator was split out at all. That 2 kWh is the price of
+keeping the bounded form, and it is stated rather than hidden.
+
+⚠️ **TWO LEADS, AND CONFUSING THEM IS HOW A CHECK GETS WRITTEN WRONG.** The cap
+bounds `i_w − target`, the command this cycle EMITS, at one step — which is what
+makes the unwind one cycle. `Decision.i_w − prev_w`, which is what TEL-10's
+`loop_lead` publishes, is measured against the command the PREVIOUS cycle left
+standing, and the emitted command is itself one step further on: the published
+figure is bounded by **two** steps. Both bounds are asserted, each against its
+own number.
+
+### The two recorded deadlocks, driven rather than argued
+
+`control.py` names two encodings that produce a permanently stuck loop, and a
+gate written on the integrator is exactly the edit that brings them back.
+Neither is reachable here and both are test cases in `test_telemetry.py` part 4:
+
+* **the shrink-only encoding** — *"only corrections that shrink |i_w|"* is
+  unsatisfiable for both signs whenever the correction is larger than twice the
+  integrator, and the loop then sits at its last value forever (measured before
+  the fix: 0 W held indefinitely into a 2 kW import). SAFETY-48 is not a shrink
+  rule; it caps the lead beyond one slew step and only while the slew binds.
+* **`i_w == 0.0`** — `main.py` resets the integrator to exactly 0.0 on every
+  stop and every reseed, and *"may not wind further in the direction it is
+  already pushing"* has no referent there. SAFETY-48 does not touch that gate;
+  the first push from zero is driven and asserted to move.
+
+And a third, specific to this card: **the cap cannot latch.** The flag is not
+carried, and after the cap `|i_w − slewed| = cap`, so the next cycle's command
+covers it in one step and the slew stops binding — after which the integrator
+accumulates freely again. The driven check asserts the command still walks all
+the way to the rail on a railed export.
+
+## 5. What this card COSTS, stated rather than smoothed
+
+**SAFETY-13's release buys back less.** That card's own scenario — a second
+writer holding the pack at +700 W, the command pinned, then released — settles
+at **−800 W** where release/1.0 settled at −1190 W against an integrator of
+−1194 W; and its sibling run settles at **−1200 W** where release/1.0 settled at
+−2390 W. The property AC 4 asserts is unchanged: the released command stops at
+the frozen integrator and not at the rail.
+
+⚠️ **AND THE TWO MOVED FOR TWO DIFFERENT REASONS, WHICH THE ONE-LINE EXPLANATION
+"how far that integrator had been allowed to wind" COVERS ONLY HALF OF.** Gating
+the cap on `not frozen` — one line, `if frozen: _lead_cap = float("inf")`, so
+the cap becomes a no-op while frozen — puts **part 5 back at release/1.0's
+−1190 W exactly**. That run moved because the cap **fires on frozen cycles**
+(§4). **Part 4(b) does not come back**: it is −1200 W gated and −1200 W shipped,
+against release/1.0's −2390 W, because *that* one moved for the winding reason.
+Both literals in `test_control.py` were re-baselined **with the reason beside
+them**, and the second is now asserted against `i_w` rather than against a
+number.
+
+**The alternative that avoids it was measured and rejected.** Gating the cap on
+`not frozen` as above gives export **34.71 kWh** (against 34.07), worst quarter
+**3434 W** (the same as shipped), wasted **3.49 kWh** (against 3.19) — and a
+worst observed lead of **4961 W**, i.e. no bound at all on the quantity this
+card exists to bound. A bound with an exception large enough to drive a truck
+through is not a bound. ⚠️ These four figures replace an earlier set (34.9,
+3461 W, 3.5 kWh, 4966 W) that does not reproduce on this tree with the gate
+spelled as above; the gate spelling is written out here so the next reader can
+re-run it rather than re-derive it.
+
+**One quarter-hour in 1534 is 532 W worse.** The billed figure is a MAXIMUM, and
+at the fitted plant lag the maximum improves (3739 → 3434 W); no quarter under
+SAFETY-48 reaches release/1.0's own worst. The mean moves the right way. The
+tail is reported because a maximum over 1534 quarters is decided by one of them
+— and §3a is the reason that improvement is not claimed as a benefit of the
+card: at every shorter plant lag release/1.0's own maximum is already 3434 W.
+
+## 6. The independent confirmation, which arrived as a failing check
+
+`test_control.py`'s SAFETY-39 section drives a family of 51 synthetic export
+steps through a **first-order plant this file writes itself** — no relation to
+the replay, no recorded data in it at all. It carried this assertion:
+
+> ⚠️ THE SLEW DOES NOT OWN THE OVER-ABSORPTION … Quartering the slew from 1000
+> to 250 does not reduce the over-absorption at all
+
+and it was right about the mechanism and therefore wrong about the conclusion:
+`slew_w` bounds the OUTPUT while the integrator accumulates `gain · error`, so a
+slower slew left the integrator winding for longer. Worst case over the family:
+
+| `slew_w` | release/1.0 | this branch |
+|---|---:|---:|
+| 1000 | 1005 W | **729 W** |
+| 0 (the rail, 556) | 1109 W | **550 W** |
+| 400 (the live interim) | 1285 W | **424 W** |
+| 250 | 1330 W | **326 W** |
+
+**The ranking inverts.** Before: slower is worse, monotonically. After: slower is
+better, monotonically. Two plant models that share nothing agree on the sign,
+which is worth more than either alone — and it means SAFETY-39's *"gain is the
+next constant to re-derive"* is now only half true: with the lead bounded, the
+slew owns a share of the over-absorption it did not own before. `gain` is still
+not touched here, for SAFETY-39's own reason: two live control-law constants
+moving in one release makes the next measurement uninterpretable.
+
+⚠️ **AND THE RIG SAYS THE SAME THING, WHICH MEANS TWO COMMITTED TRANSCRIPTS
+CHANGED MEANING UNDER THIS CARD.** `tools/slew_sim.py --slew` runs the same
+derivation on admin/goodwe's `plantsim.Plant`, a third model again. Worst-case
+over-absorption over its 51-step family, `slew_w` from 1000 down to 250:
+
+| `slew_w` | 1000 | 800 | 700 | 600 | 556 | 500 | 400 | 300 | 250 |
+|---|---:|---:|---:|---:|---:|---:|---:|---:|---:|
+| release/1.0 | 958 | 1107 | 1133 | 1058 | 987 | 1029 | 1150 | 1143 | 1081 |
+| **this branch** | 777 | 734 | 663 | 563 | 553 | 507 | 435 | 358 | 321 |
+
+release/1.0's row is flat and non-monotone and **800 really is better than 556**
+on that column — SAFETY-39 measured it correctly and its §3 sentence is true of
+the law it was written against. This branch's row falls monotonically. So
+SAFETY-39's record is not retracted; it is given a **forward reference**, and
+`slew_sim.py`'s own narration now reads `SLEW_LEAD_STEPS` out of the control law
+it imported and says which of the two tables it is printing. MUTATION.md habit 8
+— a committed transcript is a check, and a transcript whose prose contradicts
+its own table is a failing one.
+
+## 7. Verified by breaking it
+
+**The law.** `test_telemetry.py` part 4 and `test_control.py`'s SAFETY-39
+section. The mutation table is in `test_telemetry.py`'s header.
+
+**The instrument** (MUTATION.md habit 8 — anything under `tools/` that a
+document quotes is subject to the battery):
+
+| # | mutation to `app/control.py` | what the instrument did |
+|---|---|---|
+| I2 | the whole SAFETY-48 block deleted | **REFUSED**, exit 1, `NOTHING HAS BEEN MEASURED` — not a zero delta |
+| I3 | the anchor line itself edited | **REFUSED**, same message |
+| I3b | `SLEW_LEAD_STEPS = 1000` — the cap present but inert | **every row +0.00**, which is the honest report that the block is doing nothing |
+| I4 | `SLEW_LEAD_STEPS = 0` — full back-calculation | every row moves further; this is the rejected form's number in §4 |
+
+I3b is the one that matters: it proves the delta in §3 is caused by the block
+and not by the two runs differing for some other reason.
+
+**The law**, driven in the CI image on a purged tree, fingerprinted before,
+after and after the revert:
+
+| # | mutation to `app/control.py` | bytes | reds |
+|---|---|---:|---|
+| L1 | the whole SAFETY-48 block deleted | −195 B | 5 in `test_telemetry.py`, 4 in `test_control.py` |
+| L2 | `SLEW_LEAD_STEPS = 0` — the velocity form | +0 B | 4 + 3 |
+| L3 | `SLEW_LEAD_STEPS = 12` — a cap above the rail | +1 B | 4 + 3 |
+| L4 | the cap applied unconditionally, outside the slew branch | −92 B | 1 + 0 — **and it was a SURVIVOR of all thirty files before that check existed** |
+| L5a | the `min`/`max` FUNCTION names exchanged | +0 B | 5 + 5, one of them `test_control.py`'s own "frozen integrator never deadlocks" over 13 041 states |
+| L5b | the two BRANCH BODIES exchanged — the other reading of "the cap on the wrong side" | +0 B | 5 + 4, and it does **not** reach the deadlock sweep |
+| L6 | the lead measured against `prev_w` rather than the command emitted | +0 B | 6 + 3 |
+
+⚠️ **L5 AND L6 ARE BOTH ZERO BYTES** — `min`/`max` and `slewed`/`prev_w` are
+each the same length — so no fingerprint and no byte delta can see either, and
+one of L5a's reds is `test_control.py`'s own *"frozen integrator never
+deadlocks"* sweep over 13 041 states, written by SAFETY-13 for a different
+reason.
+
+⚠️ **THREE OF THESE COUNTS WERE WRONG AND ARE RE-MEASURED ABOVE, WHICH IS
+MUTATION.md's REPORTING RULE 3 APPLIED TO THIS CARD'S OWN TABLE.** The earlier
+row gave L5 as 2 + 5 and L6 as 4 + 3; driven again in the CI image on a `cp -a`
+of this tree, purged, `:ro`, one file at a time, they are **5 + 5** and
+**6 + 3**. ⚠️ **AND "L5" NAMED TWO DIFFERENT MUTATIONS.** "`min`/`max` swapped"
+can mean the function names exchanged or the branch bodies exchanged; they are
+both red, they are both the cap on the wrong side, and they give different
+counts (5 + 5 against 5 + 4) and reach different checks. A row that writes one
+number for a mutation a reader cannot re-derive from its own description is a
+row that cannot be re-run, so both spellings are listed. The directions in the
+original table were all correct; the counts were decoration, and decoration in
+a mutation table reads as evidence.
+
+## 7b. The transcript, quoted rather than summarised
+
+`python3 tools/replay_recorded_loop.py --sensitivity`, on this branch, 58 s:
+
+```
+THE RECORDING: 256252 meter instants over 16.00 days, loop-2026-09-02_2026-09-17
+    tick   p5 4.77 s   median 5.01 s   p95 7.86 s   (control.LOOP_TICK_S says 2.0)
+    the recorded command: extremes -5000 / +5000 W  ->  max_w 5000;  most common step above 100 W is 400 W, 9924 times  ->  slew_w 400
+    the fitted inverter: lag 7.5 s, tau 2.0 s, batt = 0.9731 x cmd -22.4 W, residual 375 W RMS above the SoC floor
+
+FIDELITY - the BEFORE law replayed against the recording it came from
+    setpoint  r=0.887  mean     +601 W simulated vs     +739 W recorded
+    grid      r=0.682  mean     +195 W simulated vs     +239 W recorded
+    export       39.61 kWh simulated vs    29.43 kWh recorded  ->  the model is +35 % PESSIMISTIC about the loop's tracking
+
+THE A/B, same ticks, same disturbance, same plant, same seed
+                                 release/1.0     SAFETY-48       delta
+    export kWh                         39.61         34.07       -5.54   the cost
+    import kWh                        116.07        111.20       -4.86
+    battery sign reversals           2992.00       2770.00     -222.00
+    wasted throughput kWh               4.67          3.19       -1.48
+    worst 15-min offtake W           3738.67       3433.94     -304.74   ⚠️ THE BILLED ONE
+    recovery events                   549.00        612.00      +63.00
+    recovery median s                 232.06        199.04      -33.01
+    recovery p99 s                    849.00        849.94       +0.94
+    recovery max s                    901.06        898.40       -2.66
+    unrecovered (>900 s)               53.00         31.00      -22.00
+    |i_w - prev_w| p99 W             3361.12        800.00    -2561.12
+    |i_w - prev_w| max W             9200.00        800.00    -8400.00
+    slew-limited ticks              16392.00      11654.00    -4738.00
+    mean quarter delta W                                         -2.39   over 1534 quarters
+    worst quarter delta W                                      +532.27
+
+SENSITIVITY - the ranking, not the watts
+      variant                               export kWh           worst quarter W   mean quarter dW
+      plant lag 5.0 s                32.1 ->     27.2         3434 ->     3434             -1.02
+      plant lag 10.0 s               75.4 ->     68.3         3954 ->     3434             -4.65
+      plant tau 8 s                  56.5 ->     49.8         3995 ->     3605             -3.30
+      gain 1.0135, offset -26        46.8 ->     39.3         3713 ->     3434             -3.27
+      slew_w 555.6 (the rail)        36.5 ->     34.4         3434 ->     3434             -0.17
+      gain 0.3                       28.1 ->     27.0         3434 ->     3434             +0.16
+
+    (58 s)
+```
+
+⚠️ **`--sensitivity` IS THE RANKING AND NOT THE WATTS.** The export figure moves
+by a factor of two across these plants; what does not move is the direction —
+**on export**. ⚠️ **THE `worst quarter W` COLUMN IS NOT THE SAME KIND OF
+EVIDENCE AND THIS PARAGRAPH USED TO TREAT IT AS IF IT WERE.** Three of its six
+rows read `3434 -> 3434`, and that is not "the direction holds": it is
+release/1.0 *already sitting at 3434 W* on those plants, with nothing for the
+card to improve. §3a sweeps the lag properly and finds the same thing at every
+lag ≤ 5.0 s. The billed-quarter improvement in the A/B table above exists at one
+plant, the one `fit_plant()` selects by an objective that separates it from its
+neighbour by 0.3 %.
+
+Two rows deserve naming rather than rounding: at `slew_w: 555.6` (the rail) and
+at `gain: 0.3` the mean quarter-hour delta is −0.17 W and **+0.16 W** — ties,
+not improvements. Both are regimes where `|error| > slew_w / gain` is rarely
+satisfied (1333 W at `gain: 0.3`, 926 W at the rail against a measured median
+onset error of 1114 W), so there is little for the card to bite on. That is the
+mechanism agreeing with itself, and it is also the honest answer to "would this
+still be worth shipping if the tuning moved": at `gain: 0.3` it would not be.
+
+## 8. What this card does NOT establish
+
+* **Nothing here drives an inverter.** The replay is a model with a 375 W
+  residual and no arbiter in it. The closed-loop answer comes from the rig or
+  from a live run — SAFETY-47 records why a shadow run cannot give it.
+* **The live tick is 5.0 s, not `LOOP_TICK_S`'s 2.0 s**, measured off 9924
+  recorded 400 W steps and off the meter's own cadence. It is wrong in the SAFE
+  direction (a slower meter makes `validate.py` rule 10 conservative) and is NOT
+  changed here — re-deriving `SLEW_RAIL_FRAC` is a refusal boundary on a live
+  install and belongs to its own card. It is recorded in the tool's header and
+  printed on every run.
+* **The brief's plant figure was close but not exact.** It quoted
+  `delivered = 1.0135 × command − 26 W, r = 0.992` at a 4–6 s publish lag. On
+  this 16-day window, above the SoC floor, the same relation measures
+  `1.00 × command − 28 W, r = 0.977` at a best-fit pure delay of **7.5 s**. The
+  conclusion — the inverter is a pure follower and the plant is not the problem
+  — survives; the coefficients are the ones in §2.
+* **The brief's cost figure is larger than this measurement.** It quoted ~14 kWh
+  of avoidable export and 65 % of site export inside 7.9 % of the time. Measured
+  here: **5.5 kWh** avoidable of 39.6 kWh modelled (29.4 kWh recorded), with
+  42 % of export inside the 6.3 % of ticks that are slew-limited and 69 % within
+  ±60 s of one, over 15.3 % of the time. The concentration claim holds; the
+  avoidable-kWh figure does not, and the difference is not reconcilable from
+  here because the reconstruction it came from was discarded.

goodwe_controller/DECISIONS/SAFETY-52-a-battery-that-refuses.md

@@ -0,0 +1,110 @@
+# SAFETY-52 - a battery that refuses is asked for 0 W
+
+**Decided 2026-09-27 by the owner, on the phase A plan (option D3). All four
+questions answered yes.**
+
+## The defect
+
+At the BMS cut-out the battery gives ~0 W whatever it is asked. The saturation
+freeze (`control.py`, `frozen`) then holds the request where it stood, and its
+SAFETY-13 exit cannot fire, because a reading of ~0 against a large ask lies
+inside the interval a limit can produce. The request stood at +5000 W for
+11.87 h on 2026-09-06 and at +1940 W for 3 h 55 m on the bus on 2026-09-19. It
+moved again only when the grid error changed sign. SAFETY-48's lead cap only
+changes where `i_w` parks (one slew step ahead instead of at the rail). When
+the request moved after the reading went flat, the stale-reading gate won
+instead and ran SAFETY-59's ~70 s trip cycle.
+
+## What was decided
+
+1. **A refused direction is held at 0 W**, reason `battery refuses`. It engages
+   in `compute()` when the freeze has held `SETTLE_CYCLES` and the reading is
+   below `REFUSED_BELOW_W` (100 W, the probe's own answer) against an ask beyond
+   `saturation_w`. The drop to 0 skips
+   the slew limit (it only removes an ask nobody meets). The direction is
+   carried like `sat_count` (`refused=`, `Decision.refused`).
+2. **A 200 W probe every 15 minutes, 34 s long** (`PROBE_W`, `PROBE_EVERY_S`,
+   `PROBE_S`; twice `BATT_OBLIGED_S`). A reading of at least 100 W in the held
+   direction ends the refusal, during a probe or not. 200 W is below `freshness.MOVE_W` (250 W), so a probe cannot arm
+   the gate. The clock is main.py's `now_mono`; `compute()` stays clockless.
+3. **A gate trip while the loop is frozen on a ~0 W reading is a refusal** for
+   control (`Controller._refusal_from_stale`). This is what stops the ~70 s
+   cycle. The log keeps SAFETY-56's two-explanation wording.
+4. **No SoC in the loop.** SAFETY-25 Option A stands. Nothing reads SoC.
+
+Other exits: the loop wants the other direction (charge is accepted at the
+floor), control stopped or started, another writer on the wire (the arbiter
+reseed). A gap in the readings keeps the refusal, because the gate's own stop is
+what seeds it.
+
+**One inverter only.** At N>1, OPT-09's `pack` limit already closes an empty
+battery's discharge end and moves its share. There, a one-unit gate trip must
+not refuse the site. `compute()` is passed `refused=None` there, and that path
+is release/1.0's law unchanged (the `i_w=None` equivalence sweep in
+`test_control.py` still holds).
+
+## Evidence
+
+`test_refusal.py` drives the real Controller and gate (the 09-06 and 09-19
+shapes, recovery with no sign change, the probe cadence, every exit).
+`tools/replay_refusal.py` replays the 16-day capture, same model as
+`replay_recorded_loop.py`, and should be read for deltas:
+
+| plant | law | gate trips | request >1 kW above delivery | longest held | import / export kWh | worst 15-min |
+|---|---|---|---|---|---|---|
+| fitted | old | 85 | 113.3 h | 16.57 h | 112.0 / 35.2 | 3434 W |
+| fitted | new | 130 (133 after review) | 11.4 h | 0.21 h | 112.3 / 35.4 | 3456 W |
+| offset 0 W | old | 1010 | 102.2 h | 16.58 h | 112.0 / 35.2 | 3434 W |
+| offset 0 W | new | 85 | 6.1 h | 0.33 h | 111.9 / 35.1 | 3434 W |
+
+**Traced in review (#141).** The +22 W worst quarter is the old law's worst
+quarter too. There the old law stands at +2060 W on a pack giving 0 W, and the
+new law asks 0 W, which the fitted plant answers with its -22 W offset: 22 W
+charged from the grid. The fit above the floor reads `batt = cmd - 28 W`, so a
+real inverter asked 0 W may do the same. Of the 71 new-law trips with no
+old-law trip within 2 min, 59 come 85-97 s after an answered probe. The offset has lifted the modelled pack
+just above its floor, the probe is answered, control ramps, the pack empties
+again mid-ramp, and the gate trips, which re-seeds the hold. The other 12
+follow an other-direction exit the same way. On a site this is one
+`STALE_READING` ERROR line per answered probe at most, and only on a battery
+that answers a probe and then cuts out again. Catching the re-cut before the
+gate needs a faster engage than `SETTLE_CYCLES`, which accuses a healthy slow
+battery, so it is left to SAFETY-58/59. After the review changes below the
+fitted-plant row reads 133 trips (the delivery exit now also catches answers
+that arrive after the probe window); the other figures are unchanged. Rejected alternatives and their figures are in
+the phase A plan: bounding the integrator by demand made the worst quarter
++541 W worse or cycled the gate 3368 times, and an SoC envelope needs the
+configured floor to be right and needs SoC.
+
+## Review changes (#141)
+
+- **"Gives nothing" is below 100 W, not below 500 W.** At `saturation_w` a
+  battery derated to 100-499 W (cold, a tapering battery) was held at 0 W for
+  ~93 % of the time: 300 W derated gave 86 Wh in 4 h against 1 200 Wh on the
+  old law. The capture has 0.11 h in that band, so the replay does not move.
+- **Any delivery ends the hold, not only an answered probe.** With
+  `meter_poll_s: 1` the 12 cycles last 12 s, less than a healthy battery's
+  reading lag (up to `BATT_OBLIGED_S`, 17 s). That engaged on a healthy step and
+  held it for 15 min. Now the late reading ends it within seconds (2 s held in
+  `test_refusal.py` part 5b).
+- **N>1 is stated as a limit in DOCS.** The pack limit there covers an empty
+  battery only when its cut-out level is configured right.
+
+## Not covered
+
+A battery that gives a steady part of the ask (e.g. a 500 W keep-alive) is a
+genuine limit (SAFETY-13 case a) and still holds its request.
+
+## What SAFETY-58 and SAFETY-59 must take into account
+
+- **SAFETY-58** (the first read after a rest trips at once): a probe never arms
+  the gate (200 < 250 W), but the refusal seeding reads the trip. If 58 delays
+  the first verdict, the seed arrives later. The 09-19 shape then needs the
+  compute-side engagement (12 cycles) to win, which it does only while the
+  request stands still. Keep `test_refusal.py` part 4 green.
+- **SAFETY-59** (DOCS says a ~70 s pattern proves a failed register): with this
+  change a refusing battery no longer produces the pattern at one inverter. The
+  DOCS text should say so, and that the `battery refuses` reason is the
+  discriminator the add-on now has. At N>1 the old pattern can still occur.
+- If either changes `MOVE_W`, `PROBE_W` must stay below it.
+  `test_refusal.py` part 2 checks the inequality.

goodwe_controller/DECISIONS/SAFETY-56-what-the-gate-cannot-tell-apart.md

@@ -0,0 +1,181 @@
+# SAFETY-56 — what the gate cannot tell apart, said in the sentence
+
+**Text only. No behaviour changes in this card**, and §5 is the measurement that
+says so: the same stimuli through the tree before and after produce a
+**byte-identical** trace of every verdict, every `reading()`, every `inputs_ok`
+and every readiness row's `(ok, warn)`.
+
+---
+
+## 1. The defect
+
+0.10.1 is regulating a real GW5000S-BP. Two messages tell the operator that
+healthy hardware has failed.
+
+**The log line**, as emitted on the reference site on 2026-09-21:
+
+> SAFETY-37: inverter-a battery-power register **is not following its own
+> command** - STALE_READING: -3 unchanged for 36 s while the standing command
+> moved 800 W to +1600 W - **the reading is not following**, so it is reported
+> as MISSING rather than as a measurement … Treating it as MISSING, which
+> commands 0 W.
+
+**The readiness row**, at the same moment:
+
+> NOT READY — battery power: `sensor.kelder_goodwe_master_stage1_goodwe_inverter_ac_power`
+> **is missing or not numeric**
+
+That entity was present, numeric and updating.
+
+**SAFETY-37's conjunction is correct and is not touched by this card** —
+`unchanged > 35 s AND |command| > 250 W AND |travel| > 250 W`. A register
+genuinely stuck against a real command is exactly what it should catch, and a
+pack that cannot comply is a state the site must stop in too. What was wrong is
+what the sentences **concluded** from it.
+
+## 2. Two worlds satisfy the conjunction
+
+| | the register | the pack |
+|---|---|---|
+| **DEAD** | has stopped reporting reality | is doing what it was told |
+| **REFUSED** | is reporting reality correctly | cannot comply — the BMS is refusing at its floor |
+
+A refused pack holds still under any setpoint, so an honest register publishes
+the same unchanged number a dead one does. **Nothing `freshness.py` is handed
+separates them.** All three sentences asserted DEAD.
+
+## 3. The live episode was REFUSED, and it is measured, not argued
+
+Off the committed capture `scenarios/safety57-2026-09-21/bus-a-2026-09-21-1030-1110.log.gz`,
+whose bytes and decoder are already graded by `test_freshness.py` part 10a:
+
+| | |
+|---|---|
+| the register | answered **-3 W for 850 s**, 10:51:24 → 11:05:34 |
+| the commands during that hold | **+260, +660, +1060 W** — discharge only, never a charge |
+| pack SoC throughout | **11 %** |
+| first **charge** command after the restart | 11:05:31 at **-400 W** |
+| the register moves | **11:05:34** — **3 s**, inside one 17.0 s obligation window |
+
+**A register that answers a reversed command inside one obligation window had
+not stopped reporting.** What would not move was the pack. The sentence the
+operator read named the one thing in the loop that was telling the truth.
+
+⚠️ What this does **not** establish: that no register is ever intermittently
+wrong. It excludes a register that had simply stopped; it cannot exclude one
+that was wrong and then right. That is the point — the new sentence claims
+neither.
+
+## 4. The fix, and why it is three sentences and not one helper
+
+Each message states **what was observed** and names **both** explanations.
+
+| where | before | after |
+|---|---|---|
+| `app/freshness.py` `_grade()` | *"…+1600 W - the reading is not following, so it is reported as MISSING…"* | *"…+1600 W. **TWO THINGS LOOK LIKE THIS AND THIS GATE CANNOT TELL THEM APART**: the register may have stopped reporting reality, or the source may be unable to comply with the command - a pack the BMS is refusing holds still under any setpoint, and an honest register then reads exactly like a frozen one. Either way the number cannot be read as this command's effect, so it is reported as MISSING…"* |
+| `app/main.py` `_read_unit()` | *"SAFETY-37: %s battery-power **register is not following its own command** - %s."* | *"SAFETY-37: %s battery-power reading **did not move under a command that did, WHICH IS NOT BY ITSELF A VERDICT ON THE REGISTER** - %s."* |
+| `app/main.py` `checks()` | *"{label}: {entity} **is missing or not numeric**"* | *"{label}: **no usable value this cycle from** {entity} - **and this row cannot tell which of two things that is**: the entity is missing or not numeric, or it is publishing a number that this controller is withholding (a freshness gate does exactly that, and names itself in a row of its own). Confirm the entity in Developer Tools before replacing it"* |
+
+**Three sentences, three wordings, no shared helper.** The first two are a log
+line about a **behaviour**; the third is a banner about a named **entity**, and
+the two answer different questions ("what did the register do" against "can I
+trust this entity"). A helper serving both would have to drop whichever half
+the other caller does not need, and the half it dropped would be the
+operator's next step. The log line names the pair **once**, inside the `%s` it
+already interpolates, rather than in both of its own halves.
+
+**No new input, and SoC is not wired.** `BOUNDS["soc"]` stays *STATED, NOT
+WIRED*; telling the two worlds apart needs the pack floor (SAFETY-32's number)
+and SoC (TEL-08's wiring), and a message honest about its own ambiguity needs
+neither. Part 11b drives the two worlds at **50 %** and **11 %** SoC and
+asserts the sentence does not move one byte.
+
+**The readiness row does not branch.** `inv.batt_fresh.stale` is on the same
+object at the same moment, and the row deliberately does not ask it: the same
+loop renders the grid and SoC rows, which have no gate, and a branch per row
+would be a second place where "why is this None" is decided. The gate already
+has a surface — `stale_note()` rides `liveness_notes()` a few rows below with
+the whole STALE_READING sentence in it — so the operator's discriminator is
+*"is that row there?"*, and part 11d asserts that row is **present in REFUSED
+and absent in ABSENT**.
+
+## 5. Behaviour is byte-identical, measured
+
+`tools/safety56_behaviour_trace.py` prints two documents from one stimulus set.
+The `behaviour` half contains **no sentence**: only `stale`, `reading()`,
+`releases`, `held`, the window bookkeeping, `inputs_ok`, and every readiness
+row's `(ok, warn)`. Run in the CI image, purged, `:ro`, against
+`origin/release/1.0` **archived out of git** and against this branch:
+
+| | |
+|---|---|
+| the committed live capture | **2390 reads**, 7 verdict edges |
+| a swept grid of command × register schedules | **66 cells × 120 reads** — 1060 stale reads, 1309 `MISSING` readings, 6 releases |
+| six driven controller worlds through the shipped read path | DEAD, REFUSED, ABSENT, HEALTHY, RELEASE, RETRIP — every read's `(batt, inputs_ok, stale)` and every `checks()` row's `(ok, warn)` |
+| **result** | `6030175ed2ab9a4143e86e89a71d45c8ab041ac1c00121a3e3e023cd2b08996c` **on both trees** |
+
+⚠️ **AND THE CONTROL IS INSIDE THE TOOL, BECAUSE AN IDENTITY BETWEEN TWO TREES
+THAT ARE THE SAME TREE IS HABIT 4.** `--compare` refuses to report "behaviour
+unchanged" unless the `sentences` halves **differ**. This card's first
+invariance run was exactly that mistake — it archived a branch whose edits were
+not committed yet, so `before` and `after` were the same code and the identity
+was perfect and worthless.
+
+Both of the tool's refusals are **driven**, not asserted:
+
+| | |
+|---|---|
+| the same file compared with itself | `REFUSED: the sentences halves are IDENTICAL…`, exit **2** |
+| `MOVE_W` 250.0 → 240.0 in the after tree | `BEHAVIOUR MOVED at 'sweep_stale_reads' / 'sweep_missing_reads' / 'sweep_trace'`, exit **1** |
+| this card | `OK: sentences differ, behaviour is byte-identical.`, exit **0** |
+
+## 6. The mutation battery
+
+Each in its own `mktemp`'d copy (habit 18), purged on the host, mounted `:ro`,
+graded by `tools/mutation_run.sh` in the CI image.
+
+| | mutation | Δ bytes | named reds |
+|---|---|---|---|
+| M1 | `_grade()` reverted to *"the reading is not following"* | -402 | **3** |
+| M2 | the log line reverted to *"register is not following its own command"* | -80 | **2** |
+| M3 | the row reverted to *"{entity} is missing or not numeric"* | -619 | **2** |
+| M4 | *register* and *source* transposed between the two explanations | **0** | **1** |
+| M5 | the second explanation deleted, the first kept | -216 | **1** |
+| M6 | *"CANNOT TELL THEM APART"* replaced by *"IN ORDER OF LIKELIHOOD"* | -13 | **1** |
+| M7 | the REFUSED world's ground truth set to the DEAD world's | 0 | **2** |
+| M8 | the row's second cause deleted | -309 | **1** |
+| M9 | `label` and `entity` transposed in the row | **0** | **3** |
+| M10 | M1 + M2 + M3 together, i.e. exactly what 0.10.1 ships | -1101 | **5** |
+| M11 | the accusation literals replaced by one that matches nothing | 0 | **1** |
+
+⚠️ **M9's first run was a defect in this card's own check, and it is the one
+worth reading.** The row was fetched with `[...][0]`. Transposing `label` and
+`entity` makes the row unfindable, so the run died on an `IndexError` — a red
+with **no name attached**, with every check after that line **ungraded**. That
+is FCST-06's shape exactly. `_s56_row()` now returns a named absence instead of
+raising, and a precondition grades it: **0 named reds before, 3 after.**
+
+⚠️ **M11 is the other one aimed inward.** `not any(...)` over an empty list is
+True, and so is one over three mistyped literals. The positive control runs the
+same predicate against the three sentences **as 0.10.1 shipped them** and
+requires it to find an accusation in every one, and every literal to match at
+least one of them (habit 7: vary one thing from an accepted baseline).
+
+## 7. What part 11 does not grade
+
+* It does not show the live episode was a BMS refusal beyond doubt — see §3.
+* It does not grade English. A sentence that named both explanations and then
+  said something useless about them would pass.
+* The `no entity configured` branch beside the rewritten row is untouched and
+  ungraded: a blank entity really is the only thing it can be.
+* The **grid-power and battery-SoC rows** go through the same rewritten line and
+  have no freshness gate today, so for them the second cause is a hypothesis
+  about this controller rather than a live possibility. That is weaker than the
+  battery-power case and is the price of not branching per row. A gate on either
+  signal — TEL-08 would be one — makes it exact.
+* **SAFETY-58 is not touched** (the first read after a long rest trips before a
+  healthy register could answer), and neither is the 710/790 disagreement
+  between `test_freshness.py` and the changelog. Both are separate cards; the
+  second has a **fourth site** at
+  `DECISIONS/SAFETY-57-the-exit-from-a-stale-verdict.md:274` that a fix written
+  off the PR table alone would miss.

goodwe_controller/DECISIONS/SAFETY-57-the-exit-from-a-stale-verdict.md

@@ -0,0 +1,388 @@
+# SAFETY-57 — the stale-reading verdict gets an exit, because its own consequence is what stopped it being tested
+
+**Status:** decided and implemented on branch `SAFETY-57`, off `origin/master` @ `6f5e8e3`
+(content-identical to `release/1.0` @ `8a57361`).
+**Card:** SAFETY-57 — *"the freshness gate has no exit reachable from inside the state it creates"*.
+**Nothing here reached the inverter.** No contact was made with 192.168.2.158 or
+192.168.2.221. The one live system touched is `sniffer@192.168.2.167`, a
+**passive** RS-485 listener with no address on the bus, and it was read only.
+
+---
+
+## 0. The five things a reader should take away
+
+1. **The live episode is reproduced from the wire, not modelled.** The capture
+   is committed, the decoder is committed, and the box that produced it was
+   running the defect — so the `0 W` in the trace *is* the add-on's own
+   `inputs missing → command 0 W`. §2.
+2. **Option 2 from the card — "do not arm the gate when the command is 0 W" —
+   already holds, and it is not the bug.** `_grade()` has required
+   `|standing| >= MOVE_W` since SAFETY-37. The trip happened at **+1060 W** and
+   the stuck state is at **0 W**; they are different moments. §3.
+3. **The decision is not "how long", it is "when".** The verdict is withdrawn
+   when the **obligation that produced it is no longer standing** — SAFETY-13's
+   shape one module over. The 17.0 s is the obligation window that was already
+   derived in the file, taken at the **floor** of its band, and which half is
+   safe is the **opposite** of SAFETY-13's. §4.
+4. **It costs 52 % exposure on a permanently dead register, and that number is
+   in the suite so it cannot be forgotten.** It is payable only because one
+   re-grading window (35 s) is shorter than both consumer holds (75 s, 85 s).
+   **No detection SAFETY-37 had is given back.** §5.
+5. **The battery had been rescuing this code by accident.** 93 trips in the
+   committed 16-day capture; median wait for the BMS keep-alive pulse that
+   cleared them **143 s**, worst **5 h 57 m**. §6.
+
+---
+
+## 1. What was there, in the terms the code uses
+
+`freshness.py`, `Freshness.submit()` and `_grade()`:
+
+```python
+if self.changed_mono is None or value != self.held:
+    ...
+    self.stale = False          # the only place the latch is cleared
+def _grade(self, standing_w, now_mono):
+    if self.stale or self.changed_mono is None:
+        return                  # sets the latch; never clears it
+```
+
+and `main.py:1777`, `inv.batt = inv.batt_fresh.reading()`, where `reading()`
+answers `None` while `stale`. `inputs_ok` sees the `None`, the site holds for
+`stale_input_s`, then files `Claim.set("safety", P_SAFETY, 0.0, "inputs
+missing")` and keeps filing it.
+
+The reason the latch exists is written in the class docstring and it is a good
+one: without it the verdict oscillates at about 1 Hz, because declaring the
+reading stale drops the command below `MOVE_W`, which un-arms the conjunction,
+which hands the held number straight back.
+
+**The defect is that the only thing that ends it is an arrival carrying a
+different number — and the state's own output is what stops the register being
+asked for one.** The log line promised the opposite, in the same sentence that
+announced the 0 W:
+
+> *Treating it as MISSING, which commands 0 W. It clears itself the moment the
+> register reports a different value.*
+
+---
+
+## 2. Reproducing it, from the wire
+
+`scenarios/safety57-2026-09-21/bus-a-2026-09-21-1030-1110.log.gz` is 3840
+verbatim frames off the RS-485 pair, 10:30–11:10 Europe/Brussels, decoded by
+`tools/decode_bus_capture.py`. The decoder reports **0 unparsed, 0 bad CRC,
+0 unknown shapes**, and its mode→sign convention is **graded off the capture**
+rather than trusted: 298 commands at or under −1000 W are each answered one
+obligation window later by a negative register reading, and not one positive.
+
+| capture time | on the wire |
+|---|---|
+| 10:51:14 | `0x0518` = **−447 W**; the loop is charging |
+| 10:51:19 | the command reverses: EMS **mode 3**, 260 W of discharge |
+| 10:51:24.7 | `0x0518` = **−3 W**. The pack is at **11 %**, the BMS refuses the discharge, the inverter idles. **The register is healthy and truthful.** |
+| 10:51:29.7 | the command reaches **+1060 W**. 800 W of travel |
+| 10:52:21.7 | the setpoint is written **0 W** — this is the add-on's own §11.1 rule 1, recorded on the wire |
+| …850.0 s | `0x0518` does not change value |
+| …790.0 s | the setpoint does not change value |
+| ~11:04 | **a person restarts the add-on** — not visible in this file, and the only thing that ends the episode |
+| 11:05:31.7 | the restarted loop commands **−400 W of charge**, which the pack accepts at 11 % |
+| 11:05:34.7 | `0x0518` = **−137 W** |
+
+⚠️ **THE CAPTURE IS CLOSED-LOOP FOR THE WHOLE PARKED INTERVAL**, which is why
+this is a reproduction and not a simulation: the box was running 0.10.0, so
+every command in the trace is the shipped code's own. The only event inside the
+window the file cannot account for is the human restart.
+
+Replaying the shipped `_read_unit` loop at 1 Hz against those two series
+(`test_freshness.py` part 10b):
+
+| | stale at | clear at | parked |
+|---|---|---|---|
+| **before** (`release_s = inf`) | 10:52:00 | 11:05:35 | **815 s**, and `reading()` is `None` on all **812** reads from the trip to the first command a human put on the wire, with the register at −3.0 W in every one of them |
+| **after** | 10:52:00 | **10:52:39** | **39 s**, with `0x0518` still answering the same **−3 W** |
+
+⚠️ **THE COUNTERFACTUAL IS `release_s = inf`, AND IT IS GRADED RATHER THAN
+CLAIMED.** With an infinite bound `_release()` never fires, `_open_window()` is
+only ever called where the register moves, and the window pair is the
+change-stamp pair — byte-for-byte the pre-SAFETY-57 conjunction. Part 10b
+asserts that by driving part 1's own fresh/stale pair through both bounds and
+comparing the verdict streams.
+
+The replay also found a **one-read trip at 10:48:14** that clears one second
+later. That is a pre-existing false positive and it is now recorded as
+survivor 5 — §7.
+
+---
+
+## 3. What the card's option 2 actually buys, which is nothing here
+
+The card offered *"do not arm the gate when the command being graded is 0 W"*
+and warned that it might hold already. **It does, and it has since SAFETY-37**:
+`_grade()` returns at `abs(standing_w) < self.bound.move_w`, and
+`test_freshness.py` part 4 has a named check on that term, added because a
+mutation removing it survived.
+
+The warning in the card is the right one and it is worth writing down: **the
+trip and the stuck state are different moments.** The gate armed at **+1060 W**,
+where the conjunction is entirely correct — a command travelled 800 W and the
+register did not move for 35 s. The site then went to **0 W** *because of the
+verdict*. An entry-side rule cannot reach a state that is entered legitimately
+and then persists. **The defect is the exit, and nothing else in the conjunction
+is touched by this card.**
+
+Option 3 — probing with a small non-zero command — was not taken and does not
+need to be. It writes to a real actuator to test an assumption, and §4's rule
+does not need a probe: the site's *normal* control resuming is the test, and it
+is gated behind the same `inputs_ok` everything else is.
+
+---
+
+## 4. The decision: which verdicts get an exit, and what the bound is
+
+> The stale verdict holds as before, **unless** the obligation that produced it
+> is no longer standing — `|standing| < MOVE_W` — **and** it has been gone
+> longer than the register would have needed to answer it. On a release the
+> latch clears and a **new grading window** opens at that instant.
+
+This is [[SAFETY-13]]'s §4 in a different module, and deliberately so: that card
+established the house answer to "a latch with no exit" and its answer was *not*
+a plain time bound but a **predicate plus a time bound**, where the predicate
+says whether the state can end on its own. Here the predicate is that **the
+question is no longer being asked.** A register under a 0 W command is obliged
+to be nowhere, so a verdict about whether it is following cannot be tested, and
+a verdict that cannot be tested may not stand for ever.
+
+### 4.1 Why the window has to re-open, and what happens if it does not
+
+`_grade()` compares the register's unchanged time against `unchanged_s` and the
+command's travel against the command standing when the window opened. If a
+release cleared the latch **without** re-opening the window, the first read at
+which the resumed command travels 250 W would re-trip immediately — the
+register would never get the 17 s in which it could answer, and the live
+episode's recovery (a charge the pack **accepts**) would be killed inside two
+seconds. Mutating exactly that (`graded_from` re-anchored to `changed_mono`,
++82 B) takes four named checks red.
+
+The new window is `BATT_UNCHANGED_S` = **35 s**, the same bound as entry,
+because it is the same question — *does this register follow the commands issued
+from now on?* — and there is no principled shorter answer to it. It is also the
+number the exposure argument in §5 rests on, so it is not free to move.
+
+### 4.2 `RELEASE_S` = `BATT_OBLIGED_S` = 17.0 s, and which half is safe
+
+The quantity needed is *has the register had its chance to answer the command
+standing now?*, and `freshness.py` already derives it as the floor of
+`BATT_UNCHANGED_S`'s band:
+
+```
+6.0 s   plant          goodwe/NOTES.md §5.9, measured 2026-08-22
+10.0 s  publisher      firmware/goodwe-master.yaml:181, update_interval: 10s
+1.0 s   this add-on    run_control()'s await asyncio.sleep(1)
+```
+
+⚠️ **IT IS THE FLOOR OF ITS BAND, NOT A SENSITIVITY PREFERENCE** — the mirror of
+`MOVE_W` taking the **ceiling** of its own for the mirrored reason.
+
+| | the question | the safe half | why |
+|---|---|---|---|
+| SAFETY-13's `SETTLE_CYCLES` | may the plant still be the **explanation**? | the **longer** half | a shorter bound stops believing the plant too early, and then it accuses |
+| this one | may the verdict still be **tested**? | the **shorter** half | being wrong *long* is the failure being fixed; being wrong *short* costs one re-grading window, and §5 bounds that |
+
+Below 17.0 s the release pre-empts the **cheaper exit** — the register answering
+the new 0 W command by itself, which clears the latch on evidence rather than on
+a timer. That is graded behaviourally rather than asserted: a register that
+answers at +16 s clears by **movement** at `release_s = 17.0` with `releases`
+still 0, and by **timer** at `release_s = 5.0`.
+
+The family is computed and printed (habit 10): `5, 16, 17, 18, 35, inf` give
+six distinct release instants, so no check in the file can confuse two of them.
+
+### 4.3 Two clocks, and the operator reads the register's
+
+`changed_mono` / `unchanged_s()` remain facts about the **register**: after a
+release they go on reporting that it has not moved for 850 s, because it has
+not. `graded_from` / `graded_s()` are the **verdict's** window. They coincide
+until the first release. Collapsing them either lies to the operator or defeats
+the re-grading, and both directions are mutated red.
+
+The stale sentence's `unchanged for N s` slot carries the **register's** number;
+a re-trip appends a clause naming the window and the grade count, so the two
+durations cannot be read as one number that moved (habit 14).
+
+---
+
+## 5. What it costs, measured
+
+Driven against a register frozen for good, 1201 reads, shipped defaults
+(`test_freshness.py` part 10c):
+
+| | parked | the held number reaches a consumer | releases |
+|---|---|---|---|
+| before | 1166 s | **35 reads (2.9 %)** | 0 |
+| after | 571 s | **630 reads (52.5 %)** | 17 |
+
+⚠️ **52 % IS PAID EVERY CYCLE, NOT OCCASIONALLY.** The period is
+`stale_input_s` (15 s) + `RELEASE_S` (17 s) parked, then one 35 s window.
+
+It is payable because of one inequality, and it is the inequality
+`test_freshness.py` part 6 has graded against the shipped `config.yaml` since
+SAFETY-37:
+
+```
+35 s  (the re-grading window)  <  75 s  (circulation_hold_s)  <  85 s  (unit_sign_disagree_s)
+```
+
+Every unbroken run of exposure is **exactly one window**, so neither consumer
+can reach a verdict inside one, and the re-trip that ends each run hands them a
+`None`, which **clears** their windows rather than accumulating into them.
+
+**And nothing SAFETY-37 detects is given back**, which is the half that makes
+this a trade rather than a regression: a permanent `None` clears those same two
+windows for ever as well, so on the shipped-before module those detectors are
+*equally* unable to speak about the unit. What the held number does reach for
+35 s is `site_batt_w`, the anti-windup input of `control.compute()` — which
+answers a large unexplained divergence by **freezing the output**, the
+conservative direction and SAFETY-13's business — and the command itself is
+derived from the **P1 meter**, never from `batt`.
+
+### 5.1 The narrowing this does NOT take, named so the next card can
+
+The live episode's register refused a **discharge** into an 11 % pack and then
+followed a **charge** three seconds later. A refusal in one direction is not
+evidence about the other, and a gate that knew the pack's floor could re-grade
+on the first command that crosses it instead of on a timer — which would shrink
+the 52 % above. That needs SoC, which this module deliberately does not take
+(see the `soc` row and TEL-08), and the pack floor, which is SAFETY-32's number.
+It is **not needed to give the state an exit**, and folding it in here would
+make the exit depend on a second measurement being right.
+
+---
+
+## 6. The measurement that says the old exit was luck
+
+`scenarios/loop-2026-09-02_2026-09-17/` replayed at 1 Hz through the shipped
+conjunction (`test_freshness.py` part 8b): **93 trips in 16 days.** The only
+thing that could clear any of them was the register carrying a different number,
+and that took:
+
+| | |
+|---|---|
+| minimum | 0.6 s |
+| **median** | **143.4 s** |
+| maximum | **21440.1 s** (5 h 57 m) |
+| at or over the live episode's 710 s | **17 of 93** |
+
+The short waits are the BMS keep-alive pulse — SAFETY-50 measured its ceiling at
+508 W — twitching `0x0518` and satisfying the clearing rule **by accident**.
+Over a fifth of the trips are cleared in under 20 s by something nothing in this
+add-on asked for.
+
+⚠️ **WHAT THAT REPLAY IS AND IS NOT.** The capture runs 2026-09-02…17 and
+0.10.0 — the first version carrying this gate — was cut on 2026-09-16, so the
+setpoint column is an **ungated** controller's. That makes each trip an honest
+register-versus-command divergence off the real bus, and it makes the post-trip
+command column something a gated box would **not** have written. The figure
+taken from it is therefore the only one that does not depend on the command at
+all — how long this register goes without changing value — and it **under**-states
+the wait, because a site parked at 0 W gives the register even less reason to
+move than the one recorded here.
+
+---
+
+## 7. Survivors, and the two things the battery found
+
+The battery is 22 mutations over `app/freshness.py`, `app/main.py` and
+`tools/decode_bus_capture.py`, plus one over the committed capture itself. All
+run through `ci_run.sh`, a mirror of `checks.yml`'s own step: a purged copy of
+the tree, bind-mounted `:ro`, one file at a time, `PYTHONDONTWRITEBYTECODE=1`.
+Per MUTATION.md habit 18 the harness's scratch file is `mktemp`ed per
+invocation and the tree is fingerprinted **after the revert** as well as before;
+every revert restored the recorded sha256 and byte count.
+
+**21 red, 1 argued equivalent, 0 unexplained survivors.** The table is in the
+PR body. Two of them are worth keeping here.
+
+### 7.1 The equivalent mutant, argued rather than rounded off
+
+Swapping `_release()` and `_grade()` in `submit()` is a **zero-byte** edit and
+survived the whole battery. **It is not a missing fixture and no fixture can
+close it**: `_grade()` acts only when `|standing| >= move_w` and `_release()`
+only when `|standing| < move_w`, so at most one of them can do anything on any
+read, whichever runs first.
+
+⚠️ **THE FIRST VERSION OF THE CODE CLAIMED THE ORDER WAS LOAD-BEARING**, in a
+`⚠️` comment, with a reason that sounded right. It was false, and the battery is
+what said so — **MUTATION.md habit 22 exactly, one card later: an explanation in
+a comment is a claim, and this one had not been run.** The comment now states
+the disjointness, and part 10 pins **that** — at 0, 100, 249, 250, 251 and
+1300 W — instead of pinning an order that is not observable.
+
+### 7.2 The sibling that survived, which is habit 11 earning its place
+
+`_release()`'s obligation test is `abs(standing_w) >= self.bound.move_w`.
+Swapping `move_w` for `unchanged_s` — comparing **watts against 35** — survived
+the file at **+5 B**, because **every fixture rested at exactly 0 W**, and 0 is
+below both 35 and 250. They separate only in the band between them, and a site
+can sit there: a peak-guard floor, a shadow substitution, any claim that wins
+with a small non-zero number. Closed by a three-point fixture at 0 / 100 / 300 W
+that asserts the 100 W case releases and the 300 W case does not.
+
+### 7.3 ⚠️ And the instrument lied once, which is habit 16's second half
+
+The first form of the `graded_from` mutation was
+`float(self.changed_mono or now_mono)`. It reported a **survivor at +21 B**, and
+the tree fingerprint showed the edit really was on disk and really did run.
+`changed_mono` is **0.0** in the dead-register fixture, and `0.0 or x` is `x` —
+so the mutant was a *no-op on the fixture*, for a Python truthiness reason that
+has nothing to do with the property under test. Rewritten as an explicit
+`is None` test (+82 B) it is red on four named checks.
+
+**A mutation is subject to every habit in MUTATION.md, including habit 4.** A
+purge, a fingerprint and a byte delta all say the edit is present; none of them
+says the edit *changed the answer on this stimulus*. MUTATION.md gains habit 19
+for it.
+
+---
+
+## 8. What this does NOT fix, said plainly
+
+**It does not tell a BMS refusal apart from a dead register**, and it does not
+try to. Both are re-graded on the same timer. §5.1 names what telling them apart
+would need.
+
+**It does not make the diagnosis right.** The line the operator reads still says
+*"battery-power register is not following its own command"*, which is wrong in a
+different way when the pack is simply empty. That wording is **SAFETY-56's**,
+together with `main.py`'s NOT READY row, and it is deliberately untouched here —
+two cards editing one sentence is how one of them silently loses. Only the
+**escape clause** was rewritten, because this card is what made the old one
+false, and part 10h has a named check asserting the diagnosis half is still
+there so that rewrite has to be a deliberate act.
+
+> ⚠️ **SINCE SUPERSEDED, WHICH IS WHAT THAT CHECK WAS FOR.** [[SAFETY-56]] is
+> the deliberate act: all three sentences now name **both** explanations and
+> accuse neither, and part 10h's check is inverted — it requires the accusation
+> to be **gone**. Nothing else in this section moved; the escape clause above is
+> still this card's and is untouched by it. See
+> `DECISIONS/SAFETY-56-what-the-gate-cannot-tell-apart.md`, and
+> `test_freshness.py` part 11 for the graded pair of worlds.
+
+**Survivor 5 is older than this card and is not closed by it.** After a long
+rest the unchanged clock is already past 35 s, so the **first** read carrying a
+travelled command trips the gate — before the 17.0 s in which a healthy register
+could have answered it. The live capture contains one (10:48:14, cleared one
+second later). Its size is one `stale_input_s` hold, during which `cycle()`
+returns at `inputs missing {n}s` and commands nothing differently. Fixing it
+means measuring the unchanged clock from when the **obligation** appeared rather
+than from the register's last move, which re-derives the 35.0 s bound and is a
+different card.
+
+**Nothing was measured on two inverters.** Inverter B does not physically exist
+(`goodwe/NOTES.md` §1.1b). Every two-unit figure in `test_freshness.py` is two
+copies of A's behaviour with different numbers passed in.
+
+**No deploy is proposed.** 0.10.0 is on the reference install and this branch's
+CHANGELOG row is filed under it only because `test_version_gate.py` part 11b
+requires the newest heading to be a version. Moving it, and deciding whether a
+version is cut, is a PKG card's.

goodwe_controller/DECISIONS/SAFETY-61-control-task-death.md

@@ -0,0 +1,106 @@
+# SAFETY-61 — the control task's death ends the process
+
+## 0. The defect
+
+`amain()` started `run_control()` as a bare task and waited on `stop`. Nothing
+watched the task. An uncaught exception in `read_inputs()`, `cycle()` or
+`publish()` ended the task silently, and `stop` was never set. The web UI, P1
+and tariff tasks kept running, and the Supervisor saw a healthy container. The
+traceback appeared only at shutdown. The ESP32's layer-1 veto zeroed the
+inverter about 30 s later, so the hardware was safe. The pack then sat at 0 W
+indefinitely while the add-on showed green.
+
+`test_control_task.py` reproduces this on the pre-fix tree. The child process
+reaches its 40 s deadline, has written no 0 W, and has logged nothing.
+
+## 1. Decision: exit with status 70 after the ordinary wind-down
+
+A done-callback on the control task (`control_task_done()`) handles the death.
+It logs the traceback at CRITICAL at the moment of death, then sets `stop`.
+`amain()` then runs the same wind-down that SIGTERM runs (`shutdown()` →
+`command_site_zero()`, then cancel, then clean up). After that it raises
+`ControlTaskDied`, and `main()` turns that into `SystemExit(70)` (sysexits
+EX_SOFTWARE). A normal stop and `run_control()`'s own refusal path both set
+`stop` before the task ends, so the callback ignores them. The refusal still
+exits with 78.
+
+**Why not restart the loop in the same process:**
+
+* `cycle()` writes controller state before its awaits: `cycle_at`,
+  `peak_guard`, `allocation`, then `target`/`reason`, then the writes. An
+  exception between those steps leaves the controller half-updated. A loop
+  restarted in the same process would continue from a state that no boot ever
+  produces. A process restart rebuilds the controller from the Store, which is
+  the path every boot already runs.
+* An unbounded retry is the invisible spin the card forbids. A bounded retry
+  would reimplement the Supervisor watchdog's own throttle: 10 restarts per
+  30 min, and 5 attempts with backoff (`apps/const.py`).
+
+## 2. What happens after the exit, verified rather than assumed
+
+* **Exit status reaches Docker.** The add-on image (s6-overlay, `init: false`,
+  `CMD /run.sh`) was run with `exec python3 -c 'raise SystemExit(70)'`.
+  `docker inspect` gave ExitCode 70. The same test with exit 0 gave 0, and an
+  uncaught exception gave 1.
+* **Supervisor 2026.08.0** (`ghcr.io/home-assistant/amd64-hassio-supervisor`,
+  source read from the image):
+  * A non-zero container exit is recorded as `ContainerState.FAILED`
+    (`docker/monitor.py`). The Supervisor logs *"App … exited with non-zero
+    exit code 70"* at ERROR (`apps/app.py container_state_changed`).
+  * The Supervisor restarts the add-on **only if the per-install Watchdog
+    toggle is on**. `watchdog_container()` returns when `not self.watchdog`.
+    The toggle defaults to **off** (`apps/validate.py`:
+    `vol.Optional(ATTR_WATCHDOG, default=False)`).
+  * Add-on containers get **no Docker restart policy**. The only
+    `restart_policy=` in the Supervisor belongs to the observer.
+  * `boot: auto` in `config.yaml` only controls starting at host boot. The
+    `watchdog:` key in `config.yaml` is a health-check URL, not a restart
+    policy, and this add-on does not set it.
+* **So on a default install the add-on stays stopped after this exit.** The UI
+  shows it as stopped, its log holds the traceback, and the Supervisor log holds
+  an ERROR line. The pack is at 0 W, which is the same physical state as before
+  this card. The difference is that 0 W is written immediately instead of after
+  the ~30 s veto, and the add-on no longer shows green. With the Watchdog toggle
+  on, the Supervisor restarts the add-on.
+* **Not verified:** an actual restart by a running Supervisor. That would need a
+  live Supervisor, and the only one available is the live house.
+
+## 3. Left open for the owner
+
+* Whether `DOCS.md` should tell installers to enable Watchdog. DOCS.md is not
+  this card's file.
+* Setting the Watchdog toggle from inside the add-on (`/addons/self/options`)
+  was rejected here, because it would change a user setting without the user
+  knowing.
+
+## 4. Scope: the siblings, and why they are not supervised
+
+* `run_tariff_refresh()` and the P1 HTTP and HA transports already catch
+  `Exception` inside their loops by design, and the values they feed are
+  age-bounded downstream.
+* The P1 MQTT source *returns* on purpose when it is misconfigured. Making every
+  long-lived task's end exit the process would turn that deliberate fail-safe
+  into a restart loop.
+* Only the control task is supervised.
+
+## 5. `hass.py`: an undecodable body is an absence
+
+A non-JSON `200` served as `text/html` was **already** treated as an absence,
+because aiohttp's `ContentTypeError` is a `ClientError`. The reads that actually
+escaped were these three:
+
+* a malformed body labelled `application/json`, which raises `JSONDecodeError`
+  (a `ValueError`);
+* a JSON body that is not an object, which raises `AttributeError` in
+  `number()` and `limits()`;
+* an undecodable error body in `call()`, which raises `UnicodeDecodeError`.
+
+All three were measured against aiohttp 3.13.5. The first two now read as
+`None`, and the third is now a failed write (`False`).
+
+## 6. Status row
+
+`checks()` now starts with a *control loop* row showing how long ago the loop
+last completed a pass. The row turns red once that age exceeds
+`FIRMWARE_INGEST_VETO_S`. The heartbeat is sent from this loop, so past that age
+layer 1 has zeroed the inverter.

goodwe_controller/DECISIONS/SAFETY-73-refusal-per-inverter.md

@@ -0,0 +1,104 @@
+# SAFETY-73 - a battery that refuses, with two or more inverters
+
+**Decided 2026-09-27 by the owner, on the phase A plan (option R). All four
+new questions answered yes. SAFETY-52's four decisions carry over.**
+
+## The defect
+
+SAFETY-52 held a refusing battery at 0 W at one inverter only. At N>1
+(`main.py` passed `refused=None`) nothing closed a unit that gives ~0 W while
+its state of charge reads above its configured cut-out, so the allocator kept
+handing it its weighted half. Measured on the real `Controller`, two units,
+house 3000 W, A cut out:
+
+| register | law | B gives | grid | A's gate trips / h |
+|---|---|---|---|---|
+| flat -4 W | old | 533 W | +2471 W | 46 (each stops the whole site) |
+| flat -4 W | new | 2000 W (its rating) | +1004 W | 1 |
+| jitter | old | 1910 W | +1094 W | 0 |
+| jitter | new | 2000 W | +1004 W | 0 |
+
+House 1200 W, which B alone carries: old +671 W (flat) and +284 W (jitter)
+standing import, new -16 W. Both cut out: old keeps asking two empty batteries
+(+1910 W each on the jitter shape), new holds the site at 0 W.
+
+## What was decided
+
+1. **A refusing unit is closed in that direction** by its own P_SAFETY unit
+   claim, source `refused`. It engages when the unit gives under
+   `REFUSED_BELOW_W` (100 W) for `SETTLE_CYCLES` (12) cycles, spanning at least
+   `REFUSED_SPAN_S` (22 s), in one direction while asked more than `PROBE_W`
+   (200 W), or when its stale-reading gate
+   trips on a held reading under 100 W. The allocator then hands its share to
+   the others within their own limits (owner decision 1). It is a hard unit
+   limit that always intersects, so OPT-11's P_MODE layer fits inside it.
+2. **It binds every strategy's ask on that unit** (decision 2): peak guard,
+   arbitrage and maintenance are placed around it like the loop.
+3. **A refusal to give power above the configured cut-out** logs INFO plus one WARNING ending
+   in `REFUSES_ABOVE_CUT_OUT` (decision 3). SAFETY-42/43 no longer report such a
+   unit: its share is 0 W, and `account()` treats it as parked.
+4. **All units refusing the same way** pass that sign to `compute()`, so the
+   site holds 0 W with SAFETY-52's law (decision 4). Probes go one unit at a
+   time.
+5. **Probe:** every 15 min for 34 s the claim becomes a pin at +-200 W and the
+   others carry the rest. The pin stands only while the resolved site target
+   asks at least 200 W its way; otherwise it would make a sibling take the
+   opposite direction, so it falls back to the closed limit for that cycle.
+6. **Exits:** a reading of 100 W or more in the held direction (probe or not);
+   100 W or more taken the other way for 12 cycles (charge at the floor; one
+   cycle of the loop overshooting through zero is not enough); stop or start.
+   On every exit the site target and integrator restart from the watts on the
+   wire, or the reopened unit is handed a parked remainder at once.
+
+**Why 200 W and not `saturation_w`.** A unit's share is often small: a 400 W
+night load split two ways asks 200 W of each. With 500 W the empty battery
+kept a phantom share that SAFETY-43's relative arm then reported as not
+delivering, the ERROR decision 3 replaces. Shares of 200 W or less that give
+under 100 W are "too small to call" in `account()`: the sibling covers the
+meter and nothing is asked of the empty battery that matters.
+
+**Why one direction throughout.** On TEST-19's flapping family a command that
+swaps sign each cycle reads ~0 through the plant's lag: 42 engagements in 21
+no-fault runs without the rule, 0 with it.
+
+**N=1 is unchanged.** Every SAFETY-73 path is gated on `len(inverters) > 1`.
+`test_refusal_units.py` part 6 runs SAFETY-52's whole suite with every
+SAFETY-73 method made to raise.
+
+## Evidence
+
+- `test_refusal_units.py`: cases a, b and c on both register shapes against
+  the old behaviour, probes and their spacing, one-at-a-time probing, the
+  recovery reseed, each exit, the small-ask and small-site-target cases, the
+  WARNING, the status row and shadow mode. Mutations U1-U13 in its docstring.
+- **No false engagements.** TEST-19's no-fault campaign (admin/goodwe
+  `sim/delivery_window.py` families, 2640 runs at N=2 and 2640 at N=1, every
+  unit executing its share) graded with the engage clause: 0 engagements, the
+  longest qualifying streak 5 cycles against 12. The grader is
+  `goodwe-session/scratch_s73/s73_nofault.py`.
+- **Recovery.** Case a, A recovering into a house that fell below the parked
+  target: worst grid +0 W with the reseed. Phase A measured -1059 W without the
+  reseed and the site hold.
+
+## Review changes
+
+- **The evidence must span 22 s, not only 12 cycles.** At a 1 s meter the 12
+  cycles were 11 s, shorter than a healthy reading's lag (dead time plus a
+  10-17 s publish). The reviewer's harness (real `Controller`, both units with
+  6 s dead time and a 13-17 s publish, load steps 300/3000 W every 2 min) then
+  refused both healthy units 10-16 times an hour, and each time the site held
+  0 W: +50-85 Wh import an hour and a +4.6 kW grid peak against +3.7 kW without
+  the refusal. At a 2 s tick there were none. `REFUSED_SPAN_S` is
+  `(SETTLE_CYCLES - 1) * LOOP_TICK_S`, so 2 s and slower ticks are unchanged.
+- **The cut-out WARNING is for a refusal to give power only.** A full battery
+  that stops taking charge is always above its cut-out level, and the WARNING
+  told the installer to check a setting that has nothing to do with it.
+
+## Not covered
+
+- A unit that gives a steady part of its ask (100 W or more) is a limit, as at
+  N=1. SAFETY-42/43 still report it.
+- `pack_permissions` stays SoC-based, so the peak guard may size a shave with a
+  refusing battery counted. The shortfall shows as `unmet_w`.
+- A wedged unit (HW-01) reading ~0 W is now shown as a refusal, not reported as
+  not delivering. Its share still moves, which is the gain SAFETY-42 measured.

goodwe_controller/DECISIONS/TARIFF-15-the-card-is-the-grader.md

@@ -85,11 +85,14 @@ refusal: the card's own point must land inside 0.02–1.00 EUR/kWh.
 
 ⚠️ **Its floor is applied to the ENERGY figure and not to the all-in one, and
 that asymmetry was found by a mutation rather than by reasoning.** The shipped
-`price_taxes_eur_kwh` is 0.06 — three times the floor — so a card read a
+`price_taxes_eur_kwh` was 0.06 — three times the floor — so a card read a
 hundred times too small comes out at 0.0016 EUR/kWh of energy, is carried over
 0.02 by the flat tax addend alone, and passes a band applied to the total. The
 hundredfold error is exactly what the band exists for. Graded from both
-directions in `test_price.py` 15e/15i and driven red as M10.
+directions in `test_price.py` 15e/15i and driven red as M10. *(Annotated
+2026-09-13: TARIFF-18 raised the default to 0.11736, nearly six times the
+floor. The asymmetry is unchanged in kind and larger in degree — the flat
+addend that carries a hundredfold-small card over 0.02 got bigger.)*
 
 ## 4. Fixed coefficients. No expression evaluation of any kind
 
@@ -155,4 +158,9 @@ granularity it was handed. Graded.
 * **The hour-varying network charge that bites Wallonia.** Separate card.
 * **Raising `price_taxes_eur_kwh` from 0.06 to ~0.12.** Separate card, and an
   owner's decision. Note §3b: the band's floor is deliberately insensitive to
-  whatever that number becomes.
+  whatever that number becomes. *(Annotated 2026-09-13: that card is
+  **TARIFF-18** and it shipped on this branch at **0.11736** — the Eneco
+  residential card for Flanders, September 2026, incl. 6 % VAT, summed from
+  Fluvius Antwerpen distribution 5,35 + bijzondere accijns 4,876 + bijdrage
+  groene stroom en WKK 1,51 c€/kWh. §3b held: the floor is still on the energy
+  figure and nothing in this module needed a new number.)*

goodwe_controller/DECISIONS/TEL-10-publishing-the-integrator.md

@@ -0,0 +1,182 @@
+# TEL-10 — the loop's integrator is published, as three site rows
+
+**Status:** decided and implemented on branch `TEL-10`.
+**Card:** TEL-10 — *"`self.i_w` is carried between cycles and published nowhere"*.
+**Nothing here reached the inverter, and nothing here can.** `app/control.py`
+is not touched by this branch; `compute()`, its returned `Decision` and every
+constant it reads are byte-identical to `release/1.0`. The diff is a controller
+recording three values it already had, and a publisher announcing three rows.
+
+---
+
+## 0. The three things a reader should take away
+
+1. **The row that matters is the one that is usually indistinguishable from
+   `Setpoint`.** With nothing binding, the command *is* the integrator rounded
+   to 10 W, so on a quiet day publishing the wrong one looks correct. §2 is
+   the fixture that separates them by kilowatts, and §4 is the mutation that
+   proves the separation is what the check reads.
+2. **`Loop reason` is a genuinely new sentence, not a second copy of one.** The
+   status page's `Why` row and `sensor.goodwe_controller_status` both carry the
+   *arbiter's* line (`loop -> -5000 W`), which prints the winning claim's NAME.
+   `compute()`'s own reason has never left the process, and `slew-limited` — the
+   value SAFETY-48 is about — appears in neither of the other two. §3.
+3. ⚠️ **Three entities are three entities.** This is an addition to a live
+   install's entity list, which TEL-07 refused to make for four per-unit rows
+   at a roster of one. The argument for making it here is in §5, and so is the
+   argument that keeps it to three rather than to one per inverter.
+
+---
+
+## 1. Why this is a card at all
+
+`self.i_w` has been a separate quantity from the command since SAFETY-04, which
+split the accumulator out of the velocity form precisely so the two could be
+bounded apart. Since then it has been:
+
+* carried between cycles by `Controller.cycle()`,
+* read by nothing outside `compute()`,
+* and written to no entity, no MQTT topic, no attribute and no log line.
+
+The consequence is not theoretical. The investigation behind SAFETY-48 needed to
+know what the integrator was doing during the export episodes and could only
+**reconstruct** it, from the grid trace plus a replay of the real `compute()`.
+The reconstruction reproduced about a third of the engagements it was checked
+against and was **discarded entirely** — so the card it was gathered for had to
+be argued from a measurement nobody could stand behind.
+
+⚠️ **And the reconstruction could not have been made to work.** `i_w` at a given
+instant depends on every cycle before it, including every one in which the
+arbiter overrode the loop and `main.py` re-seeded `self.i_w = self.target`. That
+re-seed is invisible in the grid trace. A replay can only recover the integrator
+on a run where the loop won every arbitration, which is not the run anybody is
+investigating.
+
+## 2. What is published, and against what
+
+Three rows, on the SITE device, appended after `release/1.0`'s eight sensors:
+
+| key | entity | what it is |
+|---|---|---|
+| `loop_i` | `sensor.goodwe_loop_integrator` | `Decision.i_w` — the accumulator AFTER this cycle, BEFORE the output clamp, the slew limit and quantisation, which is what its own docstring says it is |
+| `loop_lead` | `sensor.goodwe_loop_integrator_lead` | `decision.i_w - prev_w`, where `prev_w` is the command `compute()` was handed |
+| `loop_reason` | `sensor.goodwe_loop_reason` | `Decision.reason`, unmodified |
+
+⚠️ **`loop_lead` IS NOT A SUBTRACTION OF THE OTHER TWO ROWS, WHICH IS WHY IT IS
+A ROW.** `Setpoint` is the ARBITER's output, after every other strategy has had
+its say, and it is THIS cycle's; the lead is measured against the command the
+PREVIOUS cycle left standing. On any cycle where the arbiter overrode the loop,
+subtracting the two published rows gives a different number — and that is
+exactly the cycle on which `main.py` re-seeds the integrator, i.e. the cycle a
+reader most needs the real figure for.
+
+`cycle()` therefore records all three from the one `compute()` call, and names
+the command it passes (`loop_prev`) rather than re-reading `self.target` at
+publish time. `self.target` is reassigned later in the same method, so a lead
+computed at publish time would subtract a different cycle's command and call the
+answer a lead. ⚠️ **At the line as written the two expressions are the same
+value, and the mutation that swaps them is a recorded SURVIVOR** — see §4 M2.
+The name is kept for the coupling, not for a behaviour it currently buys.
+
+### The not-running branch
+
+`cycle()`'s `else` arm — stopped AND shadow mode off — already zeroes
+`self.i_w`, because no accumulation may survive the outage. The three rows are
+zeroed and `loop_reason` becomes `not-running` on the same branch. A row that
+kept repeating the last integrator there would say the loop was winding while
+nothing is being controlled.
+
+⚠️ **`auto: false` ALONE IS NOT THAT BRANCH.** The shipped `shadow_mode: auto`
+means a stopped controller still runs the whole decision path and records it
+(SAFETY-10), so the loop is live and the integrator is real. The first draft of
+the check asserted `not-running` about a loop that was running; it reads the
+shadow case as its own claim now.
+
+## 3. Why `loop_reason` is not the row that already exists
+
+`self.reason` is `Resolution.explain()`:
+
+```
+"loop -> -5000 W"                     # winner, watts
+"loop -> -5000 W, limited by soc"     # ...and which limit bit
+"CONTRADICTION between limits - commanding 0 W (loop)"
+```
+
+`Claim.set("loop", P_LOOP, decision.target_w, decision.reason, ...)` does carry
+the loop's reason INTO the arbiter — and `explain()` prints the winner's
+**source name**, never the claim's reason. So the loop's own word has always
+been built, handed over, and dropped one line later.
+
+Measured on the fixture in `test_telemetry.py` part 2, same cycle:
+
+```
+the arbiter's sentence: 'loop -> -5000 W'
+the loop's own word   : 'i-clamped'
+```
+
+## 4. Verified by breaking it
+
+Nine mutations, run in the CI image on a purged tree, each fingerprinted before,
+after, and again after the revert. The table with byte deltas and red counts is
+in `test_telemetry.py`'s header; two entries are worth repeating here.
+
+**M1 — `self.loop_i_w = loop_prev` (−3 B), the card's own named mutation:
+publish the COMMAND under the integrator's name.** The first draft of the
+acceptance check was *"the published integrator reaches its bound"*, and that
+check was **GREEN** under M1 — because the command reaches the bound too, twelve
+cycles later. MUTATION.md habit 4 in the check written to close the card. It
+asserts the **lead time** now (the integrator is at the bound at least ten
+cycles before the command is), and is red on 5 named checks.
+
+**M2 — `decision.i_w - self.target` (+2 B) is a SURVIVOR, and is reported as
+one.** At that line `cycle()` has not yet executed `self.target =
+resolution.target_w`, so the two expressions denote the same value and the
+mutation changes nothing that runs. The run was purged, which is not the
+direction stale bytecode fabricates. M2b (`decision.i_w - decision.target_w`,
++8 B) is the mutation that does change the value and is red.
+
+## 5. What was rejected
+
+**Publishing as an MQTT attribute on an existing entity.** There is no
+`json_attributes_topic` anywhere in this add-on; adding one would be a second
+convention for one card, and HA's recorder keeps long-term statistics for a
+state with `state_class`, not for an attribute. The reason this card exists is
+that nobody had history to read.
+
+**A status-page row instead.** The page is not recorded. `Why` already carries
+the arbiter's sentence and stays that way; DOCS.md gains the section that says
+how to read the three entities.
+
+**One integrator row per inverter.** §6.2's architecture is ONE integrator on
+the P1 meter whose output is then SPLIT. A per-unit copy would invent N of a
+thing there is one of, and the two copies would disagree the moment the
+allocator gave the units different shares. `test_mqtt.py` part 5 grades this at
+every roster length from 1 to 6, and the mutation that moves `loop_i` into
+`UNIT_SENSORS` is red on 8 named checks.
+
+**Adding the rows at N≥2 only, the way TEL-07 gates its per-unit rows.**
+TEL-07's gate exists because at a roster of one its four rows carry information
+the site rows already carry exactly. These three carry information NOTHING
+carries, at every roster length, including one.
+
+**A `## Unreleased` block in `CHANGELOG.md`.** `test_version_gate.py` part 11b
+refuses a changelog whose newest `## ` heading is not `config.yaml`'s
+`version:` — PKG-14's rule that the bump and the closed section are one act.
+Opening a section here would mean bumping the version, which is a packaging
+decision this card does not get to take. The operator-facing account is in
+DOCS.md; the release note belongs to whichever PKG ticket cuts the next
+version, and this file is what it should be written from.
+
+## 6. What this card does NOT establish
+
+* **It says nothing about whether the integrator's behaviour is right.** That is
+  SAFETY-48. This branch adds an observable and changes no decision; the
+  15.7-day replay that grades the behaviour is in that card.
+* **The three rows do not exist on the live install until the add-on is
+  updated**, and this branch does not update it. `tools/rehearsal/announced-
+  reference.txt` (what the BUILD announces) records them; `live-entities-
+  recorded.txt` (what the INSTALL has) deliberately does not, because an id the
+  build announces and the install lacks is a new entity, not an orphan.
+* **`loop_lead` is signed and is not a distance.** Where the integrator and the
+  command have opposite signs it is the sum of two magnitudes. A reader wanting
+  "how far behind is the command" should take the magnitude and say so.

goodwe_controller/DECISIONS/TEL-11-pv-production.md

@@ -0,0 +1,353 @@
+# TEL-11 — the PV production channel
+
+*What was decided, what it was decided against, and what the evidence was.*
+
+## 0. The problem, in OPT-10's numbers
+
+Over sixteen days at the reference site the pack reached 90 % SoC on **two** of
+them, and **20.5 kWh of surplus left the site while the pack still had room** —
+**12.6 kWh** of it with the battery **not charging at all**. That single
+measurement is upstream of most of what else was found that week: the nightly
+floor, SAFETY-37's misdiagnosis, the SAFETY-57 deadlock, a 2 h 47 min saturation
+freeze.
+
+It cannot be **attributed**, because **PV production is recorded nowhere in this
+system**. Three causes need three different fixes:
+
+| cause | fix |
+|---|---|
+| there was no irradiance | none — the site behaved correctly |
+| production was there, charge power was limited | a limit, somewhere |
+| production was there, the pack had room, the optimiser declined | **the only software defect** |
+
+Guessing between them is how an optimiser gets tuned to solve a cloud problem.
+**This card adds the channel and does not do the attribution.** Ship it, let it
+record a week, OPT-10 picks it up with data.
+
+## 1. It is an HA entity, not a register — and that is a product decision
+
+The RS485 bus this add-on speaks carries the **battery** inverter it drives. On
+nearly every site the PV inverter is a different box from a different vendor,
+reporting into Home Assistant through its own integration; it is **not** on this
+bus and there is no reason it would be. So the signal comes from an entity:
+`pv_entity` takes whatever `sensor.*` the site's PV integration provides, any
+brand HA can read.
+
+Reading a register would have been cheaper on one house and wrong for a fleet —
+the trade [[product-not-one-house]] names.
+
+## 2. The sign convention: **positive is production**, and there is no `pv_invert`
+
+> Reversed by TEL-14 (flag and negative caution): `DECISIONS/TEL-14-pv-sign.md`.
+
+### The convention is derived, not assumed
+
+Two sign rules already ship, and both are recorded in `DOCS.md`'s *Sources*
+table rather than inferred here:
+
+* `meter_entity` — **positive must mean importing** (`meter_invert` flips it);
+* `batt_entity` — **`+` = discharging** (`batt_invert` flips it).
+
+Both are *"positive = power arriving at the house's AC bus"*. Production arrives
+there too, so **positive = producing** is the continuation of the shipped
+convention rather than a fresh choice.
+
+### Why an invert flag would be over-building
+
+The question is not "could a sensor be reversed" — it could. It is what a flag
+would **buy**, and the answer is nothing, for two reasons that do not apply to
+the two keys it would sit beside:
+
+1. **Those two quantities are read by the control path; this one is read by
+   nothing.** `inv.batt` feeds SAFETY-30's per-unit sign check and SAFETY-31's
+   circulating-power sensor (`_read_unit()`'s own docstring says so), so a
+   reversed battery sensor hands the site a plausible number it then **acts**
+   on — a latch that trips when it should not, or does not trip when it should.
+   `pv_w` reaches no decision at all (§4), so a reversed PV sensor cannot
+   mislead one.
+2. **Production is unipolar, so the error is self-announcing.** Battery power
+   and grid power are legitimately negative half the time, which is exactly why
+   a flipped sign is invisible in them. A PV array does not consume: a reversed
+   sensor reads **−4 kW at noon**, in the first day of the very history this card
+   exists to create. An invert flag would let an installer *hide* that by
+   flipping it to something that looks right, and a second place for the sign to
+   be wrong is a second thing to get wrong.
+
+So: the convention is documented in `config.yaml`, both translations, `DOCS.md`
+and `app/pv.py`, the value is published **exactly as the sensor reports it**,
+and there is no flag. `test_pv.py` part 1 pins `-8 W` through unchanged.
+
+### And no negative-value alarm either
+
+The tempting middle path — warn when the reading is negative — needs a
+threshold, because a PV inverter's own standby draw makes a small negative
+reading at night entirely ordinary. Any threshold here would be a number nobody
+measured, in a card whose whole subject is not fabricating numbers. The
+published row is the detector.
+
+## 3. Absence is never zero, and it is not "dropped" either
+
+This is the constraint that shaped the publication, and the obvious
+implementation fails it.
+
+`MqttPublisher.publish()` **skips** a `None` value. That is right for
+`circulation` — its note in `main.py` says a missing per-unit reading should
+leave the last figure standing rather than publish a zero that reads as health —
+and it is **exactly wrong here**: a skipped row leaves Home Assistant holding
+the last number it was told, *forever*, and the recorder then draws a **flat
+line at that value through the outage**. Read back a week later that is
+indistinguishable from a real measurement, and if the last value happened to be
+small it manufactures precisely the *"there was no surplus to store"* conclusion
+the card exists to **test**.
+
+So TEL-11 publishes the absence, using Home Assistant's own mechanism:
+
+> `homeassistant/components/mqtt/const.py`: `PAYLOAD_NONE = "None"`.
+> `homeassistant/components/mqtt/sensor.py`, in the state-message handler:
+> `if payload == PAYLOAD_NONE: self._attr_native_value = None; return` — and it
+> is tested **before** the numeric branch, so it holds for a row carrying
+> `device_class: power`.
+> (github.com/home-assistant/core, branch `dev`, retrieved 2026-09-24. The
+> shipped MQTT-sensor documentation says the same thing in its `state_topic`
+> entry: *"a 'None' value will set the sensor to an unknown state"*.)
+
+The entity therefore goes to **`unknown`** and the recorder stores a **gap**.
+`mqtt.ABSENT_AS_UNKNOWN` is a one-key set and `test_pv.py` part 3 asserts both
+that the pv row gets this treatment **and that `circulation` still does not** —
+widening the rule silently would be a behaviour change to another card's row.
+
+⚠️ **What was NOT built, and why.** A per-entity `availability` block
+(`availability_mode: all`, an extra retained topic) would also produce a
+distinguishable state — `unavailable` rather than `unknown` — but it needs a
+second topic, a second retained message, a change to `_payload()`'s
+byte-order-sensitive key construction, and it survives restarts only if the
+retention is right. The payload route is one branch in `publish()` and one
+constant, and it is graded as **bytes on the topic** rather than as a claim
+about HA's availability handling.
+
+### Three states, not two
+
+| state | frame | wire | page |
+|---|---|---|---|
+| no source (`pv_entity` unset) | no `pv` key | no topic, no entity | no row |
+| no reading | `pv: None` | `goodwe_ctl/pv` = `None` | `PV —` + a caution naming the reason |
+| zero watts | `pv: 0.0` | `goodwe_ctl/pv` = `0.0` | `PV 0 W` |
+
+A failed read also **clears** the last good value (`_read_pv()` assigns on every
+call), so a reading never outlives its own sensor. `test_pv.py` part 2 drives a
+good read followed by a dead one, because a fixture that answers the same thing
+forever cannot reach that failure — MUTATION.md habit 9's shape.
+
+## 4. It must not become a control input, and that is graded twice
+
+### In the suite
+
+`test_pv.py` part 6 drives twelve cycles of the real `Controller.cycle()`
+against a 6 kW export and asserts the commands written to the inverter are
+**bit-identical** across `unset` / `no reading` / `0 W` / `8 kW` of production,
+with a precondition check that the stimulus commands something at all (habit 1).
+`inputs_ok` is asserted not to move either: a broken PV integration is **not** a
+missing input, because nothing computes with it.
+
+A computed census (habit 12 — the scope is derived from the tree, not typed)
+then reports which of the 33 modules under `app/` mention the material in any
+spelling, comments included. It is **three**: `pv.py`, `main.py`, `mqtt.py`. The
+scanner's own red direction is exercised on every run.
+
+### Across trees, by hash
+
+`tools/safety56_behaviour_trace.py` is the pattern; `tools/tel11_pv_trace.py` is
+this card's version of it, and **its control clause had to be different**, which
+is worth stating because the difference is the interesting part.
+
+SAFETY-56 changed wording and had to show behaviour did not move, so its
+`--compare` **refuses** unless the `sentences` halves **differ** — otherwise the
+two runs might be one tree twice. TEL-11's headline claim is the opposite shape:
+with the option unset, **nothing** differs. "The documents are identical" is the
+*result*, so it cannot also be the control. The two things proved instead are:
+
+* the two runs came from **different trees** (`app/*.py` sha256 + byte count,
+  compared, and an identity is **refused**);
+* **exactly one** side reacts to `pv_entity` — that side is the HEAD, the other
+  is a tree that does not have the option. Neither, or both, is refused.
+
+It drives 41 stimulus cells (5 grid worlds × 8 PV schedules, plus a run stopped
+part-way) and prints two documents per setting: `control` — every command
+written, every `self.target`, `inputs_ok`, the loop's three fields, the
+arbiter's resolution, the maintenance phase, tick by tick, **with no TEL-11
+material in it** — and `telemetry`, which is everything the card is allowed to
+move.
+
+Measured, in the CI image, on purged trees:
+
+```
+  HEAD is B; baseline is A (it does not react to `pv_entity`).
+  tree      A 73296909170ec789237d6e704cce9ab0d9f83b3df1495a14d2497285c3041a12
+  tree      B d5011b6a18e2e3803dc09cac0214b0378fa4c7388fc0ad8ad89b832a5c92af48
+  control   A unset 846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
+  control   B unset 846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
+  control   B set   846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
+  telemetry A unset a443a6ceaffe072b44bcd5f2ad946c1ed6c9e01b69e278eca631f7f4d7892164
+  telemetry B unset a443a6ceaffe072b44bcd5f2ad946c1ed6c9e01b69e278eca631f7f4d7892164
+  telemetry B set   4e6d1cb289a957223ad0205f732a6fec6110ce1f2032c98ad60694e67625274f
+OK  1/3  UNSET: control AND telemetry are byte-identical to the baseline tree.
+OK  2/3  SET: the control document is byte-identical with the channel switched on.
+OK  3/3  CONTROL OF THE CONTROL: the telemetry document DOES move when the
+         option is set (42 stimulus cells differ).
+```
+
+Note what clause 1 claims and clause 2 does not: **unset** is identical in
+`control` *and* `telemetry`, which is stronger than "the control path is
+untouched" — an install that does not set the option sees no change of any kind,
+including its announcement and its status rows. **Set** is identical in
+`control` only, which is the whole of "instrumentation, not an input".
+
+## 5. Genuinely optional — and not a second `price_now_entity`
+
+`price_now_entity` / `price_avg_entity` are legal **only** while
+`price_provider` is `off`, and the add-on **refuses to start** otherwise. That
+is the trap this card was told not to rebuild, and it is avoided structurally
+rather than by intention:
+
+* `validate.py` does not mention `pv_entity` at all. It cannot conflict with
+  anything, because nothing else reads it.
+* the MQTT row lives in `OPTIONAL_SENSORS`, not `SENSORS`, and
+  `discovery_payloads()`'s new `include` argument **defaults to empty**. So a
+  caller that has never heard of `pv_entity` — every fixture in `test_mqtt.py`,
+  `tools/rehearse_roster.py`, anything written next year — announces exactly
+  what it announced before. `p1_age` solves the same problem the other way
+  round, with `omit`, because it is announced by default and withdrawn when the
+  meter is off; getting that direction wrong here would have left most installs
+  with an entity nothing feeds, which is the hazard `omit`'s own note names.
+* the read is gated on the option, so an unset install makes **no state call at
+  all** — not a read that fails quietly.
+* there is **no status row** when it is unset. `peak_forecast_entity` nags when
+  it is unset because an unset forecast leaves a money guard without an input;
+  this is instrumentation, and a permanent caution on every install that never
+  asked for a PV channel is the warning spam the card forbids.
+* when it **is** set and the read fails, the row is `ok=False, warn=True` — a
+  **caution**. `status_payload()` builds `NOT READY` out of rows that are
+  neither `ok` nor `warn`, so a telemetry channel can never put a battery site
+  into `NOT READY`.
+
+## 6. The unit is read off the entity, and an unreadable one is refused
+
+`read_inputs()` guesses kW-or-W for `peak_forecast_entity` with
+`abs(raw) < 50`, and that is safe there: nobody's quarter-hour demand forecast
+is 50 W. It is **not** safe here — 30 W of real production at dusk is an
+ordinary reading, and that heuristic would publish it as 30 kW.
+
+So `pv.watts()` reads the entity's own `unit_of_measurement` and converts
+against Home Assistant's own `UnitOfPower` table (`mW`, `W`, `kW`, `MW`, `GW`,
+`TW`; every factor an exact power of ten). A sensor with **no** unit, or a unit
+outside that table, is **refused by name** and the status page says which. The
+refusal is loud; a guess would be silent, and a factor of 1000 in the one
+channel that exists to be believed a week later is the worse failure.
+
+⚠️ `BTU/h` is in HA's enum and is deliberately **not** in the table: its factor
+is a measured conversion rather than a decimal shift, no PV integration
+publishes in it, and a fabricated constant is what this repository's whole
+process exists to prevent. It lands in the refusal, by name, and `test_pv.py`
+part 1 pins that.
+
+## 7. The mutation battery
+
+Every check this card adds was driven by the mutation that defeats the claim it
+names. Method: `cp -a` of the tree per mutation into a **unique** directory,
+the edit applied there, `__pycache__` purged, the suites run in the CI image
+with the tree bind-mounted `:ro`, one file at a time. **The shipped tree is
+never edited**, so habit 18's revert hazard — SAFETY-37's harness killed between
+the edit and the `cp` that put the file back, and two harnesses sharing one
+backup path — is closed by construction rather than by a verified revert. Each
+row below records the byte delta, the file's sha256 before and after, and that
+the mutated line was **read back off disk** before the run started.
+
+| # | mutation | file | bytes | sha256 (first 16) before → after | red on |
+|---|---|---|---|---|---|
+| M1 | the `pv` row moved into `SENSORS`, i.e. announced on every install | `mqtt.py` | −79 B | `328d249b9d698ef6` → `532d3954c023bf3d` | 3 named in `test_mqtt.py`, 1 in `test_pv.py` |
+| M2 | `publish()` drops a `None` `pv` row again, so HA keeps the last number | `mqtt.py` | −98 B | `328d249b9d698ef6` → `dd54be458f446475` | 1 named (the acceptance criterion itself) |
+| M3 | `ABSENT_AS_UNKNOWN` widened past the one key it was written for | `mqtt.py` | +23 B | `328d249b9d698ef6` → `8fe571ebff3dacf4` | 1 named (`circulation` must still be dropped) |
+| M4 | a dead sensor reported as **0 W** instead of an absence | `pv.py` | −1 B | `55ba7471e9995436` → `9eecc34152b7ac12` | 4 named |
+| M5 | `_read_pv()` assigns only on a good read — a value outlives its sensor | `main.py` | +46 B | `c4d2cab34e50b5fd` → `189802aa69ce166d` | 2 named |
+| M6 | the unit is read and then ignored — a kW sensor published as watts | `pv.py` | −18 B | `55ba7471e9995436` → `ab19ef66c52f9379` | 2 named |
+| **M7** | **`self.grid = self.grid − self.pv_w` in `read_inputs()` — PV wired into the control path** | `main.py` | +106 B | `c4d2cab34e50b5fd` → `c38216edb7c5c8db` | **2 named, plus `tel11_pv_trace.py` clause 2/3 on 26 of the 41 stimulus cells** |
+| M8 | `optional_keys()` returns `("pv",)` unconditionally | `mqtt.py` | −52 B | `328d249b9d698ef6` → `86ff23efe3088ad8` | 3 named |
+| M9 | the PV caution made a `bad` row, i.e. a dead sensor is a `NOT READY` | `main.py` | +1 B | `c4d2cab34e50b5fd` → `45c74cab89943564` | 1 named |
+| M10 | the read gate removed — an unset option is read once a second forever | `main.py` | −10 B | `c4d2cab34e50b5fd` → `b67baa8aba3019e8` | 2 named, **plus two crashes** |
+
+`on_disk = True` for all ten: the mutated line was grepped back out of the file
+after the edit and before the run (MUTATION.md reporting rule 2), and no
+mutation is size-preserving, so rule 1's `+0 B` caveat does not arise.
+
+⚠️ **M10's two extra reds are CRASHES, not named checks, and that is recorded
+rather than tidied away.** Every `Hass` double in `test_inverter.py` and
+`test_telemetry.py` predates this read and has no `state()` method, so an
+unconditional PV read is an `AttributeError` rather than a failed assertion —
+habit 20's shape, a red with no name attached. Fixing those fixtures would be a
+change to what *their* checks report and belongs to whoever next touches them;
+this card's own fixture has `state()` and grades the property by name.
+
+⚠️ **M7's trace limb is where the two halves meet.** The mutant moves the
+control document on 26 of 41 cells — every cell whose PV schedule produces a
+READING. The five `none` cells and the five `zero` cells do **not** move, which
+is correct and is worth seeing: subtracting nothing, and subtracting zero,
+change nothing. A battery that only drove a dead sensor would have reported this
+mutation as a survivor for the third time.
+
+The clean tree those `before` hashes belong to: `app/main.py`
+`c4d2cab34e50b5fd`, `app/mqtt.py` `328d249b9d698ef6`, `app/pv.py`
+`55ba7471e9995436`.
+
+### ⚠️ M7 was a SURVIVOR on the first battery, and the fixture was the reason
+
+The card's **central** mutation — `self.grid = self.grid - self.pv_w` in
+`read_inputs()`, i.e. exactly the defect the whole card forbids — came back
+**green** on a six-file run at **+106 B**, on disk, purged, genuinely running.
+
+The property did not hold; the fixture could not reach it. `test_pv.py` part 6
+drove a **6 kW export over 12 cycles**, which puts the loop **against its
+rail**: the command moves `slew_w` every cycle and −6000 W and −14 000 W of
+apparent error produce the **same ramp, tick for tick**. MUTATION.md habit 23,
+with a saturated actuator in place of a coinciding value — and the habit's list
+of no-op-prone constructs is all *expressions*, so this is worth its own entry,
+which it now has.
+
+The fixture now drives a **600 W import the loop settles on**, with a
+responsive meter (`grid = base − batt`) so the error actually closes, asserts
+the resting target is well inside the rail, and asks habit 23's own question as
+its own check: **shift the meter by the same 8 kW and confirm the commands
+really would have moved.** On the first fixture that question answers *no*, in
+one line. Every number in the table above is from the battery re-run against
+the fixed tree.
+
+⚠️ **A red count is a property of the suite as much as of the mutation.** These
+name **this** tree at this commit; a later card that adds or re-bases a check
+moves the number with the mutation untouched. Re-measure rather than inherit.
+
+## 8. What none of this covers, with shapes
+
+* **Home Assistant itself.** That `None` renders as `unknown` and that the
+  recorder keeps a gap is read out of HA's source and quoted in §3; no HA runs
+  in this suite. What is graded here is the bytes this add-on publishes.
+* **Whether the operator's sensor tells the truth.** A sensor wired backwards,
+  or reporting DC where AC was meant, or a string instead of the array, is
+  published faithfully. §2 is the argument for why that is the right failure
+  mode; it is not a claim that it cannot happen.
+* **A roster of more than one.** The row is a **site** row — there is one PV
+  array as far as this add-on is concerned — so nothing per-unit exists to
+  separate, and every fixture is the shipped roster of one.
+* **The attribution.** This card records production. Whether the 20.5 kWh was
+  cloud, a limit or the optimiser is OPT-10's, and it needs a week of this
+  channel's history before it can be asked.
+* **`tools/`, the firmware and the ingress HTML** are outside part 6's census.
+* **The identity is only as wide as the stimulus.** `tel11_pv_trace.py` prints
+  its 41 cells with the documents for exactly that reason.
+
+## 9. No `CHANGELOG.md` entry
+
+`test_version_gate.py` 11b refuses a newest `## ` heading that is not
+`config.yaml`'s `version:`, and opening an `## Unreleased` section would mean
+taking a packaging decision this card does not get to take. The operator account
+is in `DOCS.md`; the release note belongs to the next PKG ticket, which should
+say that **0.10.1 → next** adds one optional key, announces no new entity on an
+install that does not set it, and changes no control behaviour.

goodwe_controller/DECISIONS/TEL-12-several-pv-inverters.md

@@ -0,0 +1,361 @@
+# TEL-12 — several PV inverters, and why a partial total is worse than none
+
+TEL-11 shipped `pv_entity` as a single `str?` in 0.11.0. The owner of the
+reference site reported **within minutes of it going live** that they have
+several PV inverters and could configure one.
+
+That is not a property of one house. A multi-string or multi-orientation roof
+routinely carries two or three inverters, each publishing its own power sensor
+into Home Assistant, and the add-on is sold to clients. So the channel had to
+become a roster.
+
+**OPT-10 is blocked on this and cannot start recording until it lands.** Which
+sets the bar: the number this channel publishes has to be one an attribution can
+believe, or the week of history OPT-10 is waiting for is worse than no history.
+
+---
+
+## 1. The surface: `pv_entities` beside `pv_entity`, and the measurement that
+decided it
+
+Two candidates, and they differ on exactly one question nobody in this
+repository could answer by reading: **does Supervisor accept a stored STRING for
+a key whose schema has become a LIST?** 0.11.0 shipped `pv_entity: str?`; the
+live install *has* a string persisted in it; and an upgrade that refuses that
+string leaves an add-on which will not start — CFG-04 §B's trap, in the other
+direction, with the schema needed to fix it pinned to the version that cannot be
+installed.
+
+It was measured, against the release image, by a new **§G** of
+`tools/supervisor_shape_probe.py` — the instrument CFG-04 built for exactly this
+kind of question:
+
+```
+docker run --rm -v "$PWD:/w:ro" -v "$PWD/tools:/probe:ro" --entrypoint python3 \
+  ghcr.io/home-assistant/amd64-hassio-supervisor:2026.08.0 \
+  /probe/supervisor_shape_probe.py
+```
+
+```
+== G. TEL-12: the SHAPE of a several-inverter PV option ==
+  PASS  the shipped defaults with a 0.11.0 `pv_entity` STRING on top are ACCEPTED - the baseline every refusal below is varied from
+        pv_entity='sensor.pv_power' pv_entities=[]
+  PASS  ⭐ THE MEASUREMENT THAT DECIDED THE SURFACE: with `pv_entity` declared as a LIST, the string an 0.11.0 install has persisted is REFUSED, and the refusal names the key - so that shape would leave the live add-on unable to start on upgrade
+        Invalid list for option 'pv_entity' in GoodWe RS485 Controller (local_goodwe_controller)
+  PASS  ...and a shipped `pv_entity: []` DEFAULT does not rescue it: deepmerge's list strategy is `override`, so the operator's string survives the merge and is refused anyway
+        Invalid list for option 'pv_entity' in GoodWe RS485 Controller (local_goodwe_controller)
+  PASS  ...(the list shape itself is fine - it is only the STORED STRING it refuses, which is what makes this a migration and not a schema question)
+        a list value validates
+  PASS  ⚠️ ONE SPELLING DOES ACCEPT BOTH - `match(.*)?` - AND IT IS REJECTED FOR A DIFFERENT REASON, MEASURED HERE: it validates NOTHING. A string passes, a list passes, and so does the integer 417; and the Configuration tab renders it as a plain text box rather than a repeatable field, so an operator cannot enter a second inverter in the UI at all
+        string=True list=True integer-417=True ui=[{"name": "pv_entity", "optional": true, "type": "string"}]
+  PASS  ⭐ THE SHIPPED SHAPE: an 0.11.0 blob - `pv_entity` a string, no `pv_entities` key at all, because it did not exist when that blob was written - validates against THIS manifest, with the new key defaulted to the empty list. The live install upgrades without touching its options
+  PASS  ...and a three-entity roster validates, per-entry, with both keys set - which the add-on resolves by REPLACEMENT and says so on its status page
+        ["sensor.pv_east", "sensor.pv_west", "sensor.pv_garage"]
+  PASS  ⭐ ...and the shipped `options:` block with ONLY `pv_entities` removed is REFUSED, BY NAME - `Missing option 'pv_entities' in root`. That is why the `pv_entities: []` default is load-bearing, exactly as `inverters: []` is: Supervisor treats a nested list as required unless its element is an OPTIONAL scalar, and `- str` is not one
+        Missing option 'pv_entities' in root in GoodWe RS485 Controller (local_goodwe_controller)
+  PASS  ...and the Configuration tab renders it as a REPEATABLE string field (`multiple: true`), so an operator adds their second and third inverter in the UI rather than in YAML
+        [{"name": "pv_entity", "optional": true, "type": "string"}, {"name": "pv_entities", "multiple": true, "required": true, "type": "string"}]
+  PASS  a DOWNGRADE to a schema without `pv_entities` drops the key with a warning rather than refusing, and leaves `pv_entity` standing - so rolling back to 0.11.0 returns the install to its single entity rather than bricking it
+
+== all cases passed ==
+```
+
+| Claim | Evidence |
+|---|---|
+| **Option 1 — `pv_entity` becomes a list — cannot ship** | §G: `Invalid list for option 'pv_entity'` on the string an 0.11.0 install has stored |
+| …and a `[]` default does not rescue it | §G: `_OPTIONS_MERGER`'s list strategy is `override`, so the operator's string survives the merge and is refused anyway |
+| …and it is not a *schema* problem | §G: a list **value** validates fine against a list schema. It is a **migration**, and a migration is a bigger ticket than this |
+| **One key CAN carry both shapes** — `match(.*)?` | §G, and reported even though it *passes*, because "no spelling accepts both" would have been a **false reason** to reject option 1 |
+| …and it loses anyway, for a measured reason | §G: it validates nothing at all — a string, a list, and the integer `417` all pass — and the Configuration tab renders it as a plain text box, so an operator cannot add a second inverter in the UI |
+| **Option 2 — `pv_entities` beside `pv_entity` — ships** | §G: the 0.11.0 blob validates untouched, the new key defaults to `[]`, three entities validate, the UI renders `multiple: true` |
+| `pv_entities: []` in `options:` is load-bearing | §G: the shipped defaults **minus only that key** are refused with `Missing option 'pv_entities' in root` — CFG-04 §B's isolated counterfactual, for this key |
+| A downgrade is not the trap in reverse | §G: a schema without the key **drops** it and leaves `pv_entity` standing |
+
+`p1_phase_import_entities` (`options: []` + `schema: - str`) is the shipped
+precedent for the pair; nothing new was invented.
+
+**So the surface is uglier than option 1 and that is the correct trade.** The
+cleanest surface that breaks the one install this card exists to fix is not the
+cleanest surface.
+
+### And `pv_entities` REPLACES `pv_entity` rather than extending it
+
+CFG-04's rule for `inverters:` ("declared, it REPLACES those six keys"), applied
+to the only upgrade path that matters. The install being upgraded **has**
+`pv_entity` set, to inverter A. Opening the Configuration tab, the natural action
+is to put *all* the inverters in the new repeatable field — and under a union
+rule that **double-counts A** unless the operator also remembers to clear the old
+key. A doubled total is the same defect as a partial one pointing the other way,
+in the one channel that exists to be believed a week later.
+
+Under replacement the effective roster is exactly what one key says, and no
+arithmetic depends on a de-duplication rule the operator has to know about. It
+de-duplicates *within* the list (a site cannot have two sensors with one
+entity_id, so a repeated id is a typo that would double that inverter), and
+`Controller.checks()` prints a **caution** whenever both keys are set saying
+which one won — a replacement nobody is told about is the "one of which silently
+wins" `config.yaml` refuses elsewhere.
+
+⚠️ It is a **caution and never a refusal to start**. `validate.py` still does not
+mention either key. A telemetry channel that could stop a battery site from
+starting would be observability with a foot in the control path.
+
+---
+
+## 2. ⚠️⚠️ The decision the card turns on: absence of ONE is absence of the TOTAL
+
+Three inverters configured, one `unavailable`. The sum of the other two is **a
+smaller number indistinguishable from a real one.** Fed into OPT-10's
+attribution it reads as *"there was less PV than there was"* — which is the "no
+irradiance" conclusion the channel exists to **test** rather than to manufacture.
+
+Two designs were genuinely available:
+
+**(a) publish the total as absent** — `pv.total()` answers `None`, the topic
+carries HA's own `None`, the entity goes to `unknown`, the recorder stores a gap.
+
+**(b) publish the partial sum alongside a count of how many contributed.**
+
+**(a) shipped.** It wins on the one question that matters, which is *who reads
+the number and when*:
+
+* The **MQTT row** is read back **cold**, a week later, by OPT-10 and by anything
+  that plots `sensor.goodwe_pv_power` over that week. A partial sum there is a
+  smaller number indistinguishable from a real one, and the count that would
+  have qualified it lives in a **second entity with its own history** — so
+  believing the total requires joining two recorder series by timestamp to find
+  out which samples to distrust. Nobody re-derives that. And it is worse than a
+  gap in exactly the direction that matters: **a gap makes the attribution say
+  "I do not know"; a partial makes it say something false.**
+* The **status page** is read **live**, by a human who wants the diagnostic. So
+  the partial information is *not* thrown away — the row names every entity that
+  did report, with its watts, and every one that did not, with its reason, and
+  states plainly that there is no site total. Different reader, different
+  instant, different rule.
+
+A count published beside the total would also carry **no information** in the
+state (a) admits: the total is published *only* when every entity contributed, so
+the count would be the constant `len(roster)`.
+
+And this **extends** TEL-11's rule rather than weakening it. `mqtt.py`'s
+`ABSENT_AS_UNKNOWN` is still exactly one key and `publish()`'s `None` handling is
+untouched: the line that turns an absence into HA's `unknown` did not have to
+change, because "absence is never zero" already covered this one layer up.
+
+### The mirror, which matters just as much
+
+A member honestly reporting **0 W** is **summed**, not treated as absent. The
+test is `watts is None`, never falsiness. Shading, a tripped string and
+nightfall are all real zeros, and a roster that blanked the site whenever one
+member read zero would report an absence **on every clear evening** and defeat
+the channel from the other end.
+
+### ⚠️ And the answer is NOT "document a template sensor that adds them up"
+
+An operator may legitimately prefer one, and `pv_entity` will happily point at
+it. Shipping it as *the* answer pushes the absence problem onto them unseen: a
+template sensor summing an `unavailable` source silently yields the partial
+total — the same defect one layer down, in a place this add-on cannot see or
+report. DOCS.md says so in those terms.
+
+### The three published states, side by side
+
+| what happened | frame | `goodwe_ctl/pv` | status page |
+|---|---|---|---|
+| no roster at all | no `pv` key | no topic, no entity | no row |
+| 1200 / 2100 / 450 W, all three | `pv: 3750.0` | `3750.0` | `PV  3 750 W` + one ok row naming all three |
+| all three answer, one of them `0 W` | `pv: 1650.0` | `1650.0` | `PV  1 650 W` |
+| one of the three `unavailable` | `pv: None` | `None` → `unknown`, recorder **gap** | `PV  —` + a caution naming the missing entity, its reason, and what the others reported |
+| all three gone | `pv: None` | as above | as above |
+
+---
+
+## 3. Still not a control input
+
+Unchanged, and re-proved at the new roster size.
+`tools/tel11_pv_trace.py` was **extended rather than replaced** — the file name
+still says TEL-11 because `DECISIONS/TEL-11-pv-production.md` §5 and
+`test_pv.py`'s mutation table quote it, and a renamed instrument makes both
+references dangle for no gain.
+
+It now produces **three** document sets per tree — `unset`, `one`, `multi` — and
+grades five claims. The roster cells live in their own document precisely so
+`unset` and `one` keep the `control` hashes TEL-11 recorded; appending cells to
+an existing document would have moved a hash whose stability is itself the
+evidence.
+
+```
+$ python3 tools/tel11_pv_trace.py --compare base.json head.json
+  HEAD is B; baseline is A - its roster cells ARE its unset cells, which is what a tree that has never heard of `pv_entities` does with them.
+  supports_roster   A False / B True   (self-reported; the verdict above is MEASURED)
+  tree      A fa92ba6a6fc6d49c0f87a494e03b530a8575212a0b2c3046629cb400ef2ae0d4
+  tree      B 0b39198015b6a5a3f7538d4157d77ecadc89311daef18fce883762d94d8351eb
+  control   A unset 846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
+  control   B unset 846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
+  control   A one   846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
+  control   B one   846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
+  control   A multi 2aafbfedfb9cc939082b36eeb7493289808fb21cd41113322d4817de0e414a30
+  control   B multi 2aafbfedfb9cc939082b36eeb7493289808fb21cd41113322d4817de0e414a30
+  telemetry A unset a443a6ceaffe072b44bcd5f2ad946c1ed6c9e01b69e278eca631f7f4d7892164
+  telemetry B unset a443a6ceaffe072b44bcd5f2ad946c1ed6c9e01b69e278eca631f7f4d7892164
+  telemetry A one   4e6d1cb289a957223ad0205f732a6fec6110ce1f2032c98ad60694e67625274f
+  telemetry B one   4e6d1cb289a957223ad0205f732a6fec6110ce1f2032c98ad60694e67625274f
+  telemetry A multi d269168ffece375027c2c18ea33631a961ff92775781884a0592d6a37d78845c
+  telemetry B multi 550a49a73f39267ba28b1e78cd12b8f5c71ef7269bbbd2e12112696be0fef1ff
+OK  1/5  UNSET: control AND telemetry are byte-identical to the baseline tree. …
+OK  2/5  ONE ENTITY: control AND telemetry are byte-identical to 0.11.0's single-entity path - the same commands, the same payloads, the same status rows, the same announcement.
+OK  3/5  CONTROL, ONE ENTITY: the control document is byte-identical with the channel switched on - PV reaches no decision.
+OK  4/5  CONTROL, THREE ENTITIES: every roster cell's control document equals its grid world's `unset` one - 30 cells over 5 grid worlds, covering three healthy entities, one dead at EVERY position, all three dead and one honestly reporting 0 W. Neither the total nor any PARTIAL total reaches a decision, and the document is byte-identical to the BASELINE tree's for the same cells.
+OK  5/5  CONTROL OF THE CONTROL: the telemetry document DOES move under a roster (30 stimulus cells differ from their grid world's unset telemetry), so 1/5-4/5 are identities this instrument could have broken. AND in no cell with a dead member does the PV row carry the partial sum of the survivors, while every cell whose members all ANSWER publishes its total - including the one where a member honestly reports 0 W.
+$ echo $?
+0
+```
+
+**The control hash is unmoved: `846a10a5b89e…` on `unset` and on `one`, on both
+trees.** The roster control document `2aafbfedfb9c…` is byte-identical between
+the two trees, which is the strongest available form of the claim — the baseline
+runs those cells with a key it has never heard of, so its control document for
+them *is* 0.11.0's.
+
+⚠️ **2/5 is a claim TEL-11 could not make.** TEL-11's baseline had no channel at
+all to be identical to; TEL-12's baseline is 0.11.0, so "one entity behaves
+exactly as 0.11.0 does" is a real cross-tree identity over **both** documents.
+`pv.total()` passes a single entity's `(watts, why)` through verbatim for exactly
+this reason, and `Controller.checks()` keeps 0.11.0's two f-strings in a
+`len(...) == 1` branch rather than generalising them.
+
+### ⚠️ TEL-11's `--compare` refusal had to change, and that is a finding
+
+TEL-11's rule was *"exactly ONE side's `set` document may differ from its own
+`unset` — that side is the HEAD"*. It was correct evidence when written, because
+`release/1.0` predated `pv_entity` entirely. `release/1.0` is 0.11.0 now, **both**
+sides react to `pv_entity`, and that refusal fires on **every honest run**. The
+discriminator is the roster instead: only the HEAD has heard of `pv_entities`, so
+only the HEAD's `multi` document fails to reduce to its own `unset` one.
+
+It is asserted from the **documents**, not from `tree.supports_roster` — a
+self-report is the tree describing itself, whereas "this side's behaviour did not
+move when `pv_entities` was set" is the tree being measured. `supports_roster` is
+printed beside the verdict so a disagreement between the two is visible.
+
+See MUTATION.md habit 24.
+
+---
+
+## 4. Mutation battery
+
+Twelve mutations, each on a **fresh `cp -a`** of the clean worktree (never
+reverted — habit 18 / TARIFF-09's method), `__pycache__` purged before the run
+and the tree checked for one afterwards, byte delta from `stat` and the edit
+confirmed on disk with `cmp`, suites run in the CI image with `checks.yml`'s own
+command one file at a time under a `:ro` mount.
+
+| mutation | bytes | reds |
+|---|---|---|
+| N1 `total()` returns the partial sum, not an absence | +42 B | 6 named in `test_pv.py` + 1 crash |
+| **N1b ⭐ THE REJECTED DESIGN: the partial sum with a contributor count** | −282 B | **10 named + the trace `REFUSED 5/5`** |
+| N2 absence tested by falsiness (`not w`) | −4 B | 2 named |
+| N3 `pv_entities` UNIONS with `pv_entity` | −27 B | 3 named |
+| N4 the de-duplication dropped | −15 B | 1 named |
+| N5 `sum` → `max` over the roster | **+0 B** | 6 named |
+| N6 the roster-of-one stops passing `why` through | +13 B | 8 named |
+| N7 `optional_keys()` back to reading `pv_entity` | −6 B | 1 named + 1 crash |
+| N8 `self.grid -= self.pv_w` in `read_inputs()` | +106 B | 3 named + the trace (52 cells on 2/5, 26 on 3/5, 10 on 4/5) |
+| N9 the roster caution made a `bad` row (NOT READY) | +1 B | 1 named |
+| N10 `entity_is_ignored()` always False | +10 B | 2 named |
+| N11 `pv_entities: []` deleted from `options:` | −18 B | 2 named in `test_translations.py` + `11 CASE(S) FAILED` in the probe |
+
+**No survivors.**
+
+⚠️ **N5 is `+0 B` — the risky delta.** `sum` and `max` are the same three
+characters, so neither the file size nor its mtime moved, and TEST-15's
+stale-bytecode defect is exactly what manufactures a survivor there. The run was
+on a fresh purged copy and `cmp` confirmed the edit on disk before it started.
+
+⚠️ **N1b is the row that matters, and it is not a defect.** It is the *other*
+defensible design, implemented and run. The point is that the checks and the
+instrument can **tell the two apart** — an unexamined partial sum is what the
+card forbids, so a check that could not see one would be decoration:
+
+```
+REFUSED 5/5: THE PARTIAL SUM IS ON THE WIRE at [('EXPORT-6K/EAST-DEAD', '2550.0'),
+('EXPORT-6K/GARAGE-DEAD', '3300.0'), ('EXPORT-6K/WEST-DEAD', '1650.0'),
+('IMPORT-3K/EAST-DEAD', '2550.0'), ('IMPORT-3K/GARAGE-DEAD', '3300.0'),
+('IMPORT-3K/WEST-DEAD', '1650.0')] … - a smaller number indistinguishable from a
+real one, which is the defect this card exists to prevent.
+```
+
+⚠️ **N8's 1/5 stays GREEN and that is correct rather than a miss.** With no PV
+entity configured `pv_w` is `None` and the leak cannot fire — which is what makes
+1/5 a claim about the **default** and 2/5–4/5 the claims about the channel.
+
+### The fixture values are the design (habit 10 and habit 23)
+
+`test_pv.py` carries **two** rosters over the same three entities, because the
+two claims need different magnitudes and one fixture cannot serve both.
+
+* **Parts 8–10: 1200 W + 2.1 kW + 450 W = 3750 W.** The sum is separable from
+  max (2100), min (450), first (1200), last (450), mean (1250), count (3) and
+  every partial of itself (2550 / 1650 / 3300) — the family is computed, printed
+  and asserted non-colliding as its own precondition. One member is in **kW** so
+  "correct against their own units" is exercised. **Not one member is zero**: a
+  member contributing 0 W could go absent without moving the sum of the rest, and
+  a fixture like that cannot tell "published the absence" from "published the
+  partial sum" — habit 23 with a coinciding value in the *fixture* rather than in
+  the plant, which is precisely the trap the brief named. Absence is driven at
+  **every position** of the roster, not at one (habit 10's fixture-as-a-SET), and
+  each position's partial is **derived from the fixture** rather than typed
+  beside it.
+* **Part 6: 1500 W + 4.5 kW + 2000 W = 8000 W.** Sized so every *partial*
+  (6500 / 3500 / 6000) would still **move** a loop settling on a 600 W import.
+  Habit 23's own question is asked twice — shift the meter by 8000 W, and again
+  by 3500 W, the smallest partial any single dead member could produce — because
+  a leak of the partial is a different mutation leaking a smaller number.
+
+### Two false results this card produced, and what they were
+
+Both were in the **instrument**, and both are recorded rather than tidied away.
+
+1. `partial_w`/`partial_wire` were first written **inside** each telemetry cell.
+   They are a fact about the *stimulus*, produced by the tool and identical on
+   both trees — so every roster cell differed from its unset reference for a
+   reason that was not behaviour, and the HEAD/baseline discriminator fired on
+   *both* sides. They live in a separate top-level `partials` map now.
+2. The `WEST-ZERO` cell (all three answer, one honestly reporting 0 W) had its
+   **true total** labelled as its "partial". 5/5 then refused the *shipped* tree
+   for publishing 1650 W, which it is required to publish. A cell with no dead
+   member has no partial to leak, and `never` is `None` there.
+
+---
+
+## 5. What none of this can see
+
+* **Home Assistant itself.** That `None` on the state topic renders as state
+  `unknown` and that the recorder keeps a gap is read out of HA's source and
+  quoted in `app/mqtt.py`; whether the long-term statistics table then
+  interpolates across the gap is HA's behaviour, and OPT-10 will be reading it.
+* **Whether the operator's sensors are telling the truth.** A sensor wired
+  backwards reads −4 kW at noon and is summed as −4 kW. There is deliberately no
+  `pv_invert` — §2 of the TEL-11 record is the argument, and it holds at a roster.
+* **A roster larger than three.** Three is the smallest size at which the sum
+  separates from the reduction family *and* absence can be driven at every
+  position. Nothing here says what twenty entities do to a cycle's latency — the
+  read is `asyncio.gather`ed across the roster for exactly that reason, so a slow
+  sensor costs what one costs, but that is an argument rather than a measurement.
+* **A PV roster combined with a two-inverter battery roster.** No fixture
+  crosses CFG-04's `inverters:` with `pv_entities`.
+* **The real MQTT transport, and wall-clock behaviour.** As TEL-11.
+
+---
+
+## 6. Not deployable as merged
+
+`config.yaml` stays at `0.11.0`, so `tools/predeploy_check.py` reports a NO-OP
+until PKG cuts a version. A CHANGELOG entry is **wanted** and was deliberately
+not written: `test_version_gate.py` 11b forbids an `## Unreleased` heading and
+the bump is PKG's call. The material an entry needs is this file.
+
+The option surface moves **76 keys → 77**, one new optional key, `pv_entities`,
+empty on every install that does not set it.
+
+**Superseded in part (UX-08, 2026-09-27):** the PV status rows no longer read 0.11.0's sentences at one entity. The owner ruled out entity ids on status rows, so 2/5 now holds for the control document only. See `UX-08-short-notifications.md`, phase 2b item 3.

goodwe_controller/DECISIONS/TEL-14-pv-sign.md

@@ -0,0 +1,83 @@
+# TEL-14 — the PV sign, declared per entity
+
+Owner report on 0.12.0: `sensor.espressif_vermogen` (ESPHome clamp) and
+`sensor.kwh_meter_actueel_vermogen` (kWh meter in the PV circuit) read
+**positive for consumption, negative for production**. At night the page said
+"✓ PV production: 13 W" — standby draw. By day production would publish negative.
+
+## 1. This reverses TEL-11 §2, and why
+
+TEL-11 §2 refused a `pv_invert` on two grounds. "PV is read by nothing in the
+control path" still holds: the flip lives in `pv.total()`, and `test_pv.py`
+part 12 re-runs part 6's 40-cycle identity with a flip set. "A reversed sensor
+announces itself" did not survive a real site: these sensors follow a different
+convention, read a plausible small positive number at night, and the only other
+fix is a template sensor, the place TEL-12 §2 says goes quietly wrong.
+
+## 2. The shape: a parallel list, `pv_invert_entities`
+
+Measured by `tools/supervisor_shape_probe.py` §H (Supervisor 2026.08.0, against
+a 0.12.0 blob); re-run it for the transcript.
+
+| shape | schema | why it lost / won |
+|---|---|---|
+| (a) `-sensor.x` prefix | accepted | invisible: the sign is a syntax only the description explains, in a field an installer fills with the entity picker's text |
+| (b) parallel list | accepted, 0.12.0 blob unchanged | **ships**: its own labelled, translated field ("PV entities whose sign is reversed"); an installer lists the odd ones out |
+| (c) dicts on `pv_entities` | **refuses 0.12.0's stored strings** | bricks the upgrade — TEL-12's trap again |
+| (c2) dicts as a third key | accepted | per-entry labels render raw (`entity`, `invert`) — probe §F; and a third PV surface |
+| (d) global bool | accepted | one sign cannot describe inverter + meter in one roster |
+
+(b)'s known cost is a typo in the second list: `pv.stray_inverts()` turns it into
+a named caution. `[]` in `options:` is load-bearing (§H, isolated counterfactual).
+Default `[]` flips nothing, so every 0.12.0 install is byte-identical (part 12).
+
+## 3. The negative caution: per entity, below −50 W
+
+The owner's two meters draw ~13 W at night, so a *correctly* signed meter reads
+about −13 W then. −50 W clears that with room for a few such devices behind one
+entity; a reversed sensor by day reads hundreds to thousands of watts below
+zero. It is tested **per entity, not on the total** (a deviation from the brief):
+three correct meters at −20 W sum to −60 W and must stay quiet, while a reversed
+−1500 W hidden inside a positive total must not. It is a caution, never `bad`;
+a wrong threshold costs a spurious or missed caution, never data. The text says
+ADD (unflipped) or REMOVE (already flipped).
+
+## 4. Mutations
+
+Fresh `cp -a` each, `__pycache__` purged, CI image, `:ro`, `--network none`;
+`test_pv.py` only unless stated. T1-T12 at 7559d21; M2/M5 are review #1628's,
+red since B1 (merged into release/1.0 @ 43b2740).
+
+| # | mutation | bytes | reds |
+|---|---|---|---|
+| T1 | flip ignored in `total()` | −45 | 9 |
+| T2 | flip applied to every member | −7 | 6 |
+| T3 | `0.0 - w` → `-w` | −5 | 1 |
+| T4 | flip written as `abs()` | −1 | 2 |
+| T5 | `_read_pv()` stops passing the flip | −26 | 7 |
+| T6 | caution threshold −50 → 0 W | −17 | 3 |
+| T7 | `[sign inverted]` marker dropped | −39 | 3 |
+| T8 | negative caution made `bad` | +1 | 1 |
+| T9 | `stray_inverts()` always empty | −50 | 1 |
+| T10 | `inverted()` stops stripping | −8 | 1 |
+| T11 | ADD/REMOVE advice swapped | +4 | 2 |
+| T12 | `pv_invert_entities: []` deleted from `options:` | −25 | 2 test_translations + 17 probe |
+| M2 | `stray_inverts()` roster ignores `pv_entity` | +15 | 2 (REPORTED CASE, PADDING) |
+| M5 | `_read_pv()` flip set not stripped | +25 | 1 (PADDING) |
+
+## 5. History
+
+OPT-10's `sensor.goodwe_pv_power` recorded since 2026-09-24 on an install with
+such sensors carries the old sign; nothing rewrites it.
+
+## 6. CHANGELOG entry for the next PKG cut
+
+Not written into `CHANGELOG.md`: `test_version_gate.py` 11b/11d refuse an
+`## Unreleased` heading (measured on this branch: 4 reds). For PKG to paste:
+
+> **`pv_invert_entities` (TEL-14).** A PV sensor that reads negative while
+> producing — typically a kWh meter or power clamp in the PV circuit — can now
+> be listed under *PV entities whose sign is reversed* in the Configuration tab;
+> its sign is flipped before the sum and the status page marks it. Empty (the
+> default) changes nothing. ⚠️ PV history recorded before you set it keeps the
+> old sign.

goodwe_controller/DECISIONS/UX-08-short-notifications.md

@@ -0,0 +1,92 @@
+# UX-08 phase 2a: short notifications, and what moved out of them
+
+The owner decided on 2026-09-27: a title of at most about 5 everyday words and a one-sentence body. A red safety alarm may use up to 3 sentences, so no action-relevant information is lost. Titles are neutral, with no "GoodWe:" prefix. HA entity ids appear only in refusals. The rule is `STYLE.md` at the repository root, the texts are in `app/messages.py`, and `test_messages.py` enforces both. The detail each notification used to carry is in DOCS.md under "Notifications", and the body links to it.
+
+**Unchanged:** every `notification_id`, every trigger and cadence (edges, SAFETY-34 re-announce, per-unit ids), every log line and every status row. The status banner and rows are phase 2b, refusals and option texts 2c, logs 2d; `ux08_allowlist.txt` lists them until then.
+
+## Where a choice was made
+1. **Severity of "not delivering" (SAFETY-42).** The notification is an *alarm*, so it may use 3 sentences. Its log line is ERROR and the alarm is latched. The page banner stays amber, as SAFETY-42 decided, because control keeps running; the two answer different questions (is control running / must a person act) and HA shows no colour on a notification. The three checks stay in their original order. Clearing it takes stop then start, and the body says so.
+2. **Figures left the bodies** of the frozen-meter card (the rail and the command), the circulating-power card (the watts and the time window) and the peak cards (the projection). None of them is needed to act, and all of them are still in the reason text that the log line and the status row carry. `test_freeze.py` and `test_watchdog.py` now pin that. The frozen-meter card can therefore no longer quote a wrong rail (SAFETY-20), because it quotes none.
+3. **The over-rating alarm keeps its numbers** (asked, sent, and which limit cut it), because they are what a fault report needs. `ClampWatchdog.facts` carries them under the same keep-the-bug rule as `reason`, so the words and the numbers always describe the same tick, with asked before sent (SAFETY-40, `test_clamp.py` part 6).
+4. **SAFETY-25 stays in the peak-reserve alarm** as its last sentence ("the reserve only limits peak shaving … down to its cut-out level"). The alarm now gives each branch its own action: at the reserve, lower it; battery level unread, check the sensor; floor unknown, set the cut-out level. That last branch is `soc_floor is None`, which happens when an inverter's cut-out level is missing, not the peak reserve (that option always has a value). Before, every branch said "lower peak_soc_floor". The title, "Battery stopped limiting the peak", is true on all three branches.
+5. **SAFETY-32 at a roster of one.** The body no longer ends in a separate "WHICH PACK" paragraph. The pack's name is part of the first sentence ("The battery of inverter-b …"), and at a roster of one that is the only difference.
+6. **Dropped as background, now in DOCS:** "charging stays blocked" (peak reserve), "why no other guard fired" (circulating power, not delivering), and the saturation-freeze distinction (over-rating). "The meter cannot see this" stays in the circulating-power card, as the owner asked.
+7. **The Details link** opens the add-on's documentation page (`/hassio/addon/<slug>/documentation`, with the slug taken from the container hostname) and names the section. A `#heading` anchor was not used because nobody has checked that Home Assistant's documentation tab renders heading ids; if it does, adding one is a one-line change. Outside an add-on container it names the section without a link.
+
+# Phase 2b: status rows and page banners
+
+Every row of the Commissioning list and every banner is now in `app/messages.py` (`row_*`, `banner_*`), and `test_messages.py` checks a rendering of each. The row and banner kinds are gone from `ux08_allowlist.txt` (200 → 168 entries). DOCS.md "Status page" explains the rows. **Unchanged:** every row's colour (ok / warn / bad), which rows show when, and the banner cascade order.
+
+## Where a choice was made
+1. **A red row may use 3 sentences (30 words).** STYLE.md gave rows 15 words; the owner allows red safety states 3 sentences. A red row needs room for what happened, the state (0 W) and how it clears. STYLE.md now says so, and the test applies it by colour.
+2. **Figures left the rows, not the product.** The reason texts (freeze, sign, circulating, delivery, peak guard) carry reason codes and limits; they stay on the ERROR/WARNING log line and the event list, as before. Rows keep the numbers a reader acts on: the stall age and the 0 W deadline, the meter age and limit, asked and sent for an over-rating, the peak limit, and "opposite for 12 of 60 seconds" while a check counts. So 2a item 2 ("also on the status row") no longer holds, and DOCS.md says "in the add-on log".
+3. **No entity id on any row**, even the green ones that used to print `sensor.x = 54`. The sensor rows name the setting (*Battery power for inverter-b*). Solar sources are numbered in the order of the settings list (*source 2 of 3*, *entry 1 of the reversed-sign list*). This retires TEL-12's rule that a one-entity site reads 0.11.0's sentence byte for byte. A `tools/tel11_pv_trace.py --compare` against a pre-UX-08 tree therefore shows the PV rows as changed telemetry, and the control documents stay equal. The per-source watts and units left the multi-source row. The total, the count and which source is missing remain.
+4. **UX-07 item 1.** `ClampWatchdog` now also counts `over_rating` and `bound` separately. After an episode, each count shows under its own alarm's title ("Power request too high: 2 times since start, not now", "Battery is not keeping up: …"). A site with both gets two amber rows where it had one.
+5. **The "Not ready" banner** is the first red row's own `banner`, or else its first sentence. The peak-reserve and over-rating rows set `banner` to their notification title. The three trips keep their own banner branches, reworded (e.g. "Inverters worked against each other. Every inverter is set to 0 W.").
+6. **How a latch clears stays on the row**, shortened: "Only starting control clears this", "A restart does not clear this", "only stopping and starting control clears this" (not delivering). SAFETY-25's sentence stays on the peak-reserve row.
+7. **Rows got an `id`** (`meter_frozen`, `direction`, `pv`, …), so tests find a row by what it is, not by its words. The page ignores it.
+8. **Left for later:** texts that rows embed from other modules and that were not flagged as rows (the month-peak line, `peakguard.explain()`, the liveness and stale notes, `shadow.banner()`). The month-peak row only lost its semicolons.
+
+# UX-09: fixes after the phase 2a test
+
+1. **The Details link follows the Home Assistant version.** HA 2026.2 added the built-in `app` panel (core #157554, frontend #28245), whose add-on pages are `/config/app/<slug>/documentation`. 2026.5 stopped registering the `hassio` panel, so `/hassio/addon/<slug>/documentation` is a 404 there (TEST-23, HA 2026.9.1). 2026.1 and older have only the old path. The one path valid on both, `/_my_redirect/supervisor_addon?addon=<slug>`, opens the Info tab, not Documentation. So the add-on reads its slug (`GET /addons/self/info`) and the HA version (`GET /info`) at start, and picks the path. An unknown version gets the current path. The hostname stays as a fallback for the slug. Phase 2a item 7 is replaced by this.
+2. **Shadow mode says "would".** The over-rating alarm and row said "sent X W" while 0 W was on the wire, and the peak alarm said "the battery is giving all it can". Both now take `shadow=`, and in shadow mode say what would have been sent and that the inverters stay at 0 W. Severity, id and cadence do not change with the mode.
+3. **"Controller" is gone from texts.** "The add-on" names who decides, and "control" names what it does, as in the existing "start control". The add-on is what the reader sees in Home Assistant, and "controller" was easy to confuse with the control board.
+4. **One term per setting, matching its label.** Four labels changed instead of the texts, because the texts' words were plainer: “Peak reserve (%)” (was "Peak guard will not discharge below"), “Battery level entity (%)” (was "Battery charge level"), and “Solar production entity / entities, per inverter / Reversed-sign solar entities” (was "PV …"). The Dutch labels already said "Zonneproductie". Option descriptions are phase 2c and were not changed, so some still say "PV".
+5. **The shadow banner and the inverter notes** are now `messages.banner_shadow()` and `row_no_setpoint` / `row_not_controllable` / `row_commands_refused`, so `test_messages.py` checks them. The red shadow banner no longer lists the latches, because 12 words cannot carry them. It says a safety stop stays on, and each latch keeps its own red row, which names it and says how it clears. The colour of a liveness row now comes from `is_live()`, not from matching "NOT COMMANDABLE" in the text.
+6. **DOCS "Notifications" and "Status page"** are written for a home owner, and the card ids, keys and log detail moved to a "For installers" part of each.
+
+# UX-08 phase 2c: refusals, error texts and option texts
+
+Validator refusals, the parse errors they carry, and every option name and description are now short. No rule, key, schema, default or exit code changed. Over 36 spoiled configurations the old and new validators refuse the same number of times. The allowlist went from 167 entries to 43, and only log lines (phase 2d) remain on it.
+
+1. **A refusal names the setting by its label and then its key**, as `messages.setting()` writes it: “Inverter rating” (max_w). The key has to stay, because `configui.problems_by_field()` shows a reason beside every key its text names. A test checks each label against en.yaml. A few reasons no longer mention keys they only named in passing, such as `price_markup_eur_kwh` in the withdrawn-provider reason, so the panel shows those reasons beside fewer settings. Each reason still names the setting that fixes it. A setting of one inverter in the list is written “Inverter rating” for inverter-b (inverters.max_w), so the panel shows it beside `inverters`, where that value is changed, and not only beside the flat `max_w` that a list does not read.
+2. **Citations moved to DOCS.** Option descriptions say "Measured value, leave it unchanged" or similar, and the record behind the value is under "For installers: where the numbers come from". The UX-01 citation check in `test_translations.py` now checks the tab for that instruction and DOCS for the record.
+3. **What left the refusals:** the shipped default in the peak-reserve reason, the superseded-default note in the levy-table reason (DOCS already covers it), the endpoints of the withdrawn providers (DOCS "Energy price providers"), the plant measurement behind `slew_w` (DOCS, beside the setting), and the leg-specific paragraphs of the tariff-formula errors. Each reason keeps the rejected value, the limit and what to change.
+4. **Not rewritten:** errors that only a code defect can raise, such as plugin-contract and argument-type checks in `price.py`, `price_forecast.py`, `static_tariff.py`, `arbitrage.py` and `main.py`, which a home owner never reads. INFO lines such as the tariff-formula preview were also left.
+
+# UX-08 phase 2d: log lines, the rest of the status page, and DOCS
+
+The allowlist is empty and its cap is 0 (43 → 0). Every WARNING and ERROR line is one plain line of at most 25 words, with no card ids, capitals or semicolons (the semicolon rule now covers log lines too). **Unchanged:** every log level, every trigger and cadence, every notification id, every row's colour and when it shows, the banner cascade, and every refusal count.
+
+1. **No code prefixes on log lines.** Nothing outside the repositories greps them, except `/home/homelab/clampwatch.sh`, a one-off site watch from 2026-09-05 that greps `OUTPUT_CLAMP` and `Engagements so far`. `OUTPUT_CLAMP` is still in the reason the line quotes; "Engagements so far" is now "Cut back N times so far". The tests that found a line by its card id (`SAFETY-37`, `SAFETY-44`, `CONTROL LOOP DIED`, `UNGRADED`) now find it by its words.
+2. **Reason texts keep their codes.** A line quotes a watchdog's reason (`%s`), such as `STALE_READING: …` or `OUTPUT_CLAMP: …`. Those are the evidence an installer searches for and many tests pin them, so they were not rewritten. The line around them is plain.
+3. **Reasoning moved to DEBUG, not deleted,** for the 10 lines marked DROP-to-DEBUG (for example the 14 768 W history behind the over-rating alarm, why SAFETY-42 reports and does not act, and the Eneco card advice). The 25-word line keeps the action and the numbers. SAFETY-57's promise stays on the ERROR line, as an ordered pair: "until it changes, or 17 s after the command drops below 250 W".
+4. **The line under the buttons** showed the newest raw action-log entry (`OUTPUT_CLAMP …`, `FAILSAFE …: SIGN_DISAGREEMENT`, `ALLOCATOR …`). Each `log_event()` call now also names a plain hint from `messages.HINTS`, and the page shows that. The action log itself is unchanged, because tests and later analysis read it, and the page no longer shows it. It stays reachable as `events` in the `status` JSON (review of #136), because some entries are written nowhere else: a dropped inverter's reason, the unplaced watts, the peak guard's projection and the shadow decision.
+5. **The top table.** *Why* is `messages.why()`: the arbiter's winner and limit in words ("Keeping the grid near zero: 440 W, held back by the peak limit"). `self.reason` keeps `Resolution.explain()` for the log and the checks. *Tariff*, *Price history*, *Arbitrage* and *Shadow mode* keep every figure TARIFF-11 and SAFETY-47 put there, each in its own slot, in words. Labels: *Battery level*, *Solar production*, *Power request*.
+6. **The month-peak row became two rows**, because one sentence of 15 words cannot hold the peak, its time, its share of the limit and TARIFF-13's coverage figure. The store's state at start (`restore_state`) left the row: it is the INFO line at start.
+7. **The peak guard rows** name the projection first and the limit second, as before (SAFETY-38). The blind row says what it means for the owner: the battery does not charge until the period can be measured again.
+8. **Wording that changed meaning-carrying words**: "command and meter point opposite ways" is now "the power went the wrong way" (banner) and "…went against what the add-on asked" (row). The N=1 banner still names the meter, the N≥2 texts still say "own power". The inverter range reads "up to 5 000 W each way" instead of "-5 000 W to 5 000 W".
+9. **Refusals are counted as shown.** Setting placeholders are expanded to label and key, and the long cases the 2c test found are driven through the validator. Seven refusals were shortened. The card refusals no longer show `c_eur_per_kwh`, `vat_pct` or "its own card", and a text that does not parse says "not valid near character N" instead of the parser's words. A missing value shows as *empty*, not `None`.
+10. **The panel's key match** no longer files `inverters.max_w` under the flat `max_w`.
+11. **The Supervisor question at start** is one INFO line with a real reason (a timeout's own text is empty, so the error type is named).
+12. **DOCS**: a glossary ("Words used on this page") explains control board, isolator and Developer Tools once. Card ids left the headings and sit on a *For installers* line under each. The links to the renamed headings were updated.
+
+# UX-10: the last plain-language leftovers (after the 2d test)
+
+**Unchanged:** every safety behaviour, every alarm's log level (WARNING and ERROR stay), every notification id, trigger and cadence, the banner cascade, and every row colour except the meter row right after a start (item 6).
+
+1. **Why the 2d scan missed the clamp lines.** Part 3 reads a log call's own literal and counts `%s` as one word. The clamp lines are `"…software fault: %s …"`, and the text in `%s` was built elsewhere, by `loop_clamp_note()` and `ClampResult.describe()`. So the scan passed a line whose logged text had a semicolon, "BUG SIGNAL", "clamped" and "1 times". The same was true of every quoted reason. Part 6 closes the gap. It lists every dynamic part of every WARNING+ line as data (a number, a name, a path, a library's own error text) or as a built text, and a new part in neither list fails. Each built text is produced by the real code (the watchdogs, `decide()`, `loop_clamp_note()`, `MigrationReport.explain()`) or, for a family of builders, by every template of it (`PriceRead.no_data`, `Gate.block`). The text and the line as logged are then checked. A mutation shows the 2d clamp text is caught on both clamp lines.
+2. **A quoted reason gets the red-alarm shape**, 3 sentences of at most 30 words, and not the 25-word line limit. It is the evidence behind an alarm, and it keeps its code and its limits, which the owner asked to keep. The alarm shape is STYLE.md's existing rule for the texts behind a safety stop, so no new limit was made up. Rewritten: `OUTPUT_CLAMP` (both kinds), `METER_FROZEN`, `CIRCULATING_POWER`, `STALE_READING` (SAFETY-56's two explanations and "cannot tell which" kept, in order), the peak guard's reasons, the state-migration report, the price feed and price history reasons, and the maintenance and trading gate reasons. "Software fault" left the clamp reason, because the ERROR line around it already says it.
+3. **Codes are one token.** `PEAK GUARD`, `PEAK GUARD FLOOR-LIMITED` and `PEAK GUARD BLIND` read as capitals, so they are now `PEAK_GUARD`, `PEAK_GUARD_FLOOR_LIMITED` and `PEAK_GUARD_BLIND`, like `OUTPUT_CLAMP`. Nothing in admin/goodwe or in the scripts under `/home/homelab` greps them (checked). `/home/homelab/clampwatch.sh` greps `OUTPUT_CLAMP`, which stays.
+4. **Top table.** *Price history* writes "96 prices over 24 hours for 26 Sep", joined by commas. *Tariff* writes the spacing as "one every 15 minutes or every hour". "Not final yet" was dropped, because a plan is provisional exactly when it holds an estimated price (`n_carried` counts the provisional points), so the estimated count already says it.
+5. **Levels and noise.** The shadow line of every cycle is DEBUG, and "Shadow mode is on/off" is INFO: it follows a setting or a button, and the banner, hint and event are unchanged. aiohttp's access log is on only at log level debug. A settings warning is logged once per start (a filter on `goodwe.config`, WARNING only, so refusals are untouched), because the validator runs twice at start. When Home Assistant restarts, `hass.Outage` says so in one WARNING line for the REST API and the meter websocket together, puts the library's text on DEBUG, and says at INFO when both answer again. INFO lines lost "§8.3", ISO timestamps, "banked" and "keys ARE", and error texts lost "NOT_OBSERVED", "did NOT land" and "AND".
+6. **Display bugs.**
+   - "Why: Other" during a latched per-inverter stop: `main.py` turns a safety winner into its claim's reason, and "sign disagreement" (and "unsplit", main.py's own refusal to split) had no entry in `WHY_WINNER`. The mapping is now `main.why_key()`, and part 7 finds every `Claim.set()` in the code and checks that every key it can produce has words.
+   - Red "Meter: no reading for 0 seconds" after a restart: until the first reading arrives, `P1Ingest.stale` is true, and the age is the time since start. The row now reads amber "waiting for the first reading" while that age is inside the limit. **Colour change, justified:** red at 0 s contradicted the limit the same row prints, and once readings exist the row is red only past that limit. Amber, not green, because control waits for the reading. Past the limit it is red as before. `stale` itself, which gates control, is unchanged.
+   - "A reading is missing for 0 seconds" stuck at 0: with the meter reading gone, the grid value stops changing, so the loop runs a cycle only every `cycle_floor_s`, and the line was computed once per cycle. The age is now counted when the page asks. The hold and its 15 s escalation are unchanged.
+7. **Review: the line as logged gets the shape too.** Part 6 first checked the quoted reason alone, so a title, a 2-sentence reason and two tails still logged as 4 sentences ("Power request too high …: OUTPUT_CLAMP: … +5000 W. The command this cycle was +1000 W. Control is still running. Cut back 1 time so far."). Part 6 now also checks the whole line: at most 3 sentences, none over 30 words. The wrappers became one sentence each, the circulation and peak guard reasons two, and `STALE_READING`'s fixed limits moved from the reason to a DEBUG line beside the ERROR (its release clause stays, pinned by test_freshness). The clamp lines for one inverter are pinned at 30 words at most: `OUTPUT_CLAMP: computed +9000 W, cut to the +5000 W rating, command now +2000 W`. Several clamped inverters read as one sentence of asked/sent pairs; which limit bound each is on its own action-log row and in the notification. Totals above 30 words remain on the direction, delivery, frozen-meter and stale lines (up to 74 words). Shortening them is a follow-up: the direction and delivery reasons are also persisted in state.json, and the direction one is pinned byte-for-byte in test_watchdog.
+8. **Home Assistant 400 while it loads** now reads "Home Assistant refused number.set_value for number.x (error 400, no details). The entity may still be loading, or the value is out of range." A body with more than "400: Bad Request" is still quoted. Still WARNING, still once a minute, still a failed write.
+9. **Witness** (admin/goodwe): the resolved push says "after no answers from … to …", as the resolved card does. The YAML with every title and message stripped is identical.
+
+# UX-11: safety log lines give the code, the figures go to DEBUG
+
+**Unchanged:** every trigger, latch, threshold and alarm log level (the WARNING and ERROR lines stay), every notification id and cadence, every row colour and the banner cascade. No notification is added.
+
+1. **One plain sentence and the code.** A WARNING/ERROR line that reports a safety reason (direction, delivery, stuck meter, stale reading, peak guard, circulation, over-rating) now ends in the reason's code, taken by `messages.reason_code()`. The reason itself, figures and limits included, is on a DEBUG line logged right after it ("Evidence for inverter-a: …"), and the action log entry carries it as before. Part 6 checks that pairing in the code. Circulation and the clamp lines were not among the five named, but they break the same 25-word rule, so they follow the same pattern. The clamp numbers stay in the notification (phase 2a item 3).
+2. **The reasons and `state.json` are unchanged.** `reason` stays the evidence text, so what is saved has the same format as before. An old state file therefore loads and displays like a new one: every saved reason has opened with its code since it was first written (checked in the git history), and that code is all the ERROR line reads. The saved text goes on the DEBUG line. A stop saved without a reason shows `REASON_NOT_SAVED`. `test_messages.py` part 7 restarts from a state file holding the old long texts. `test_watchdog.py` pins the meaning (the code first, then command, reading, time and both limits, in that order) and, since the text did not change, still the bytes.
+3. **The 25-word rule is checked as logged.** Part 6 fails any WARNING+ line over 25 words with its built text filled in. Nine non-safety families still run long (tariff plan words, price feed reasons, the state migration report, write refusals and claim scope errors that only a software fault raises, maintenance, trading gate and price history reasons). They are listed with a reason in `LONG_LINE_OK`, capped at 9, and a listed family that gets shorter fails until it is removed. Shortening them is a follow-up.
+4. **The meter row's "the add-on log shows why" is now true.** When the meter goes quiet past its limit, the add-on logs one WARNING per episode, not one per cycle, and an INFO line when readings return. A meter that flaps (on `ha_signed` a healthy meter under a flat load can go 42–97 s between changes) logs at most one such pair per 10 minutes, and the episodes in between go to DEBUG. This is a new log line, not a new alarm: it has no notification and changes no decision.
+5. **The Why line past the 15 s hold** names the missing reading ("No usable meter reading for over 15 seconds: 0 W", or the battery power or level of an inverter), instead of "A reading is missing: 0 W".
+6. **Action log:** "25 engagement(s)" is "25 engagements", and "SHADOW MODE OFF - …" is "Shadow mode off: …". "SHADOW MODE ON" was not named in the card and is left as it is.
+7. **Review: after a restart the figures go on the action log too.** `log_level` defaults to `info`, so the DEBUG evidence line is not seen by default, and `events` starts empty. Each restored stop (direction per inverter and site, delivery, circulation) now also writes its saved reason to the action log ("FAILSAFE inverter-a, saved before the restart: …"), and the page's event line gets the same plain words the live stop gives. `LONG_LINE_OK` also refuses a key whose text is a safety reason, not only a `reason_code` key.

goodwe_controller/DECISIONS/UX-13-one-layout-table.md

@@ -0,0 +1,79 @@
+# UX-13 — one layout table, and why UI code may now name an option key
+
+**Status: DECIDED 2026-09-27 (owner approved the UX-13 design and mockup).**
+Card 6ab979852f3eca02fb40f69e. Amends [[UX-02]] §3.1. Design note and
+mockup: `goodwe-session/UX-13-design.md`, `UX-13-mockup.html`.
+
+## 1. What UX-02 said, and why it no longer fits
+
+UX-02 built the configuration panel from the Supervisor's schema, so
+`app/configui.py` contains "no option key, no label and no rule", and
+test_selfconfig.py part 5 checks that the page script names no key. That kept
+a second copy of the option surface from drifting, and it is why the panel is
+a flat list of fields in schema order.
+
+UX-13 needs things a schema cannot say: groups and sub-groups, a slider in kW
+for a value stored in W, a picker for an entity, a field shown only for one
+meter source, locked measured values, a Simple view and a setup wizard. It
+also needs page fields that are not options at all: one inverter card that is
+stored as six flat keys, solar rows that become `pv_entity` or `pv_entities`,
+a contract and two prices that become `static_profile` JSON, and a region
+that becomes the levies figure. None of that can be read off the schema, so
+some code has to name option keys.
+
+## 2. The decision
+
+Option keys may appear in UI code in exactly two files:
+
+- **`app/uilayout.py`**, the layout table: screen → group → part → field, with
+  control, unit, display scale, step, entity kind, when it is shown, whether it
+  is on the Simple view or a wizard step, and whether it applies now or after a
+  restart. Every option in `config.yaml` is a field, `DERIVED` or `HIDDEN`,
+  exactly once.
+- **`app/uimodel.py`**, the derivations the table names: `options_to_ui()` and
+  `ui_to_options()`. It may name only the keys it writes.
+
+What UX-02 made authoritative stays authoritative:
+
+- **Ranges** come from the schema (`uilayout.range_of()`); the table writes
+  none. A unit holds no digit.
+- **Labels and help** come from `translations/*.yaml` by key. Page-only fields,
+  group titles and choices are in `app/ui_text/*.json`, held to STYLE by
+  test_messages.py.
+- **Rules** stay in `validate.py`. It gains a warning tier (`validate.Note`,
+  "warn" or "info") for the page. A note never blocks a save, and passing the
+  notes list does not change the refusals returned.
+- **The stored blob** is still the one truth. The page model carries the stored
+  values of every derived key (`keep`). A derivation whose page fields are
+  unchanged writes those values back untouched, so a blob the page cannot
+  express survives a save of another field.
+
+## 3. How it is held
+
+- test_uilayout.py fails when `config.yaml` gains an option, or an inverter
+  field, that the table does not place. It also checks that uimodel.py names
+  only the keys it writes and that web.py and haentities.py name none.
+- test_uimodel.py round-trips options → page model → JSON → options for every
+  validator call the suite made at 652097a (`scenarios/ux13/`), the TEST-23
+  option files and config.yaml's defaults. All must be identical.
+- `tools/ux13_validator_calls.py compare` runs those calls through the old and
+  new validator. At P0: 261 calls, 158 refused, no refusal changed.
+- test_selfconfig.py part 5 still checks the old page script; P1 moves the page
+  into `app/static/` and the same check applies there.
+- P2: the Installer view (`app/static/settings.js`) draws from
+  `app/uipage.py`, which serialises the table and names no key itself
+  (test_uilayout part 5, test_settings part 2). The view posts its page model
+  to the existing `/config/validate` and `/config/save`, which turn it into
+  options with `ui_to_options()` before the shipped validator runs. No route
+  was added.
+- P4: the setup wizard draws the same model by each field's `wizard` step.
+  Its tables (`KETTLE`, `SHADOW`) are in `uilayout.py`, and its live checks
+  are rules, so they are in `validate.py` (`setup_checks`). settings.js still
+  names no key. See [[UX-13-setup-wizard]].
+
+## 4. What this costs
+
+The table is a second place that knows the option surface, which UX-02 set
+out to avoid. The cost is bounded by the coverage test: an option added to
+config.yaml and not placed here fails CI, rather than silently missing from
+the page. Changing a key's type or range needs no change here.

goodwe_controller/DECISIONS/UX-13-setup-wizard.md

@@ -0,0 +1,101 @@
+# UX-13 P4 — the setup wizard, and when it opens by itself
+
+**Status: DECIDED 2026-09-28 (P4 dev; the design and mockup were approved
+2026-09-27).** Card 6ab979852f3eca02fb40f69e. Builds on
+[[UX-13-one-layout-table]]. Design note: `goodwe-session/UX-13-design.md` §1, §3.6.
+
+## 1. What the wizard is
+
+The Setup tab draws the Installer view's page model one step at a time: a
+field is on step *n* when its `uilayout.Field` says `wizard=n`. It uses P2's
+controls, `/config/validate` and `/config/save`. No route was added.
+`uilayout.py` holds what a field cannot say: the kettle table (`KETTLE`), the
+optional step and the shadow switch (`SHADOW`). Step 5 has no battery modes
+yet (OPT-11); it says they come later.
+
+A step moves on when no refusal is anchored to one of its shown fields
+(`uipage.step_problems`). A refusal on a hidden field, a field on no step or
+no field at all blocks the last step, which lists every refusal.
+
+## 2. When it opens by itself (`uipage.setup_needed`)
+
+The page opens `#setup` only when it is opened with no route, and only when
+`/config/model` gives a reason:
+
+- **`no_power_request`**: the stored options name no inverter to control.
+- **`first_start`**: this boot found no `/data/state.json` (`Store.fresh`), the
+  Store has no `setup_done` and no `auto` key, and control is not started.
+  `auto` is the key Start/Stop writes. The startup gate exits 78 before the
+  controller writes the Store, so a new install's first good boot is fresh.
+
+"Never started" alone is not enough: both TEST-23 add-ons have `auto_start`
+off and no `auto` key, and one has run in shadow for weeks (review of PR #146,
+R1). So a Store read from a file is an old site, and it is never sent to the
+wizard. A new install that restarts before the page is opened is not sent
+either, and its Setup tab still works. A site that runs control, or ever
+started or stopped it, is never sent. Without a Store the answer is no. The wizard's save writes
+`setup_done` (an ISO time) to the Store. A save from the Installer view does
+not.
+
+**Not decided here, for the owner:** the add-on exits 78 before it serves the
+page when the stored options name no power request entity, which is what a
+brand-new install ships (config.yaml's `setpoint_entity: ""`). So on a truly
+new install the installer fills in "Inverter setpoint entity" on the
+Configuration tab first, and the wizard opens on the next page visit.
+Serving a setup-only page from a refused configuration would change the CFG-01
+startup gate and UX-02 §4 ("the panel is not available when it is most
+needed"), so it is left as an open question.
+
+## 3. The kettle test and the sign checks
+
+Step 1 reads the meter's entities now (`GET ha/entities?entity=`, one
+`hass.state()` read, in W) before and after a kettle is switched on. The
+change, not the sign, decides: a rise of at least 500 W keeps `meter_invert`
+off, a fall turns it on. For a net entity or import and export, a fall cannot
+be fixed by an option, so the step is not passed and the page says what to
+check. A meter the add-on reads itself (HomeWizard, MQTT) cannot be read by
+the page, so the test is skipped and Home shows the direction after the
+restart. The installer may skip the test, because a cloud can fake a fall;
+the last step then warns, and after a fall it says the reading went down.
+
+The battery and solar signs cannot be forced from the page, which never
+commands an inverter. The last step reports each battery's reading with its
+direction ("reads 800 W charging now, so check the inverter shows the same")
+and warns when a solar entity reads below zero without its "reads negative"
+switch. It also warns when meter + solar + battery, all known, add up to a
+house using less than -300 W: a battery sensor reversed while giving power.
+An idle or charging battery cannot be judged that way.
+
+## 4. The last step
+
+`validate.setup_checks()` sits beside the rules because it names option keys.
+It reads nothing itself: `web.py` passes a Home Assistant entity list at most
+5 s old, the running options, the running meter reading and today's price
+count. Tiers are ok, info, warn and bad. A power request entity missing from
+Home Assistant is **bad**, because a write to it is answered 200 (SAFETY-77)
+and only the entity list can tell. So is Home Assistant not answering, since
+the list is then unknown. The wizard does not save while anything is
+bad. It then saves through P2's path (`setup: "done"`) and asks for the
+restart as the second, confirmed request, with a dialog that names the 0 W.
+The shadow switch is on by default and writes `shadow_mode: on`, which holds
+every inverter at 0 W after a restart even if control is started. Off keeps the
+stored value, or `auto` if that was `on`. The switch goes only on the model the
+wizard posts, never into the page model the Installer view also saves.
+
+## 5. The stale save lists only what moved (P2 test, finding a)
+
+`/config/model` remembers the last 16 blobs it handed out, by fingerprint. On a
+stale save the add-on compares that blob with what is stored now, so the banner
+lists only the other surface's changes. `changed` (stored against the posted
+blob) is unchanged for the classic page's "theirs → mine" list. When the
+fingerprint was not handed out by this process, it falls back to `changed`.
+
+## 6. How it is held
+
+- test_setup.py: the steps and tables, the kettle logic (and the page's copy of
+  it), step blocking, the first-run rule on new and TEST-23 sites, the live
+  checks, the save through the P2 path, the stale fix, and the words.
+- tools/ux13_wizard_blobs.py produces every blob the wizard can save from a new
+  install and three TEST-23 sites (88 accepted by the shipped validator). At P4
+  all 88 were accepted by Supervisor 2026.08.0's `AppOptions`, offline, 78
+  keys each.

goodwe_controller/MUTATION.md

@@ -172,7 +172,7 @@ manufactures them from a **fixture**: the check runs, the assertion is
 evaluated, the sentence above it is true — and the numbers it compares are
 arranged so that the failure it describes could not have changed the answer.
 
-It is not hypothetical and it is not rare. ELEVEN instances in two weeks; four
+It is not hypothetical and it is not rare. TWELVE instances in two weeks; four
 were found by review, two - CFG-04's fixture pair - by an author's own mutation
 battery, which is the cheaper place, one by review again, in the one
 place nobody had thought to point the rule at: not a check in the suite, but a
@@ -414,6 +414,44 @@ same place twice, the check is decoration.
 
   The general habits are **14** and **15** below.
 
+* ⚠️ **SAFETY-47 IS THE TWELFTH, AND IT IS THE SECOND INSIDE A COMMITTED
+  EVIDENCE ARTIFACT.** `DECISIONS/SAFETY-10-shadow-mode.md` §6 tabulated a live
+  run and a shadow run agreeing on `arb_power_w`, on the reason **verbatim**
+  and on the arbiter's winner, and concluded that shadow mode reaches the same
+  decision. **Two independent reasons it could not have gone red, and closing
+  either one alone closes nothing:**
+  * its fixture is `peak_cap_w: 15000` against a 350 W house, so the capacity
+    guard never engages and the thing whose invariance is being claimed —
+    SAFETY-45's sizing of the buy leg from the billed-quarter meter — is in the
+    run and **inert**. ⚠️ **The harness's own comment says so**: *"at this
+    scenario's `peak_cap_w: 15000` it is not binding anyway"*. The rule was
+    written down beside the check it disabled and nobody read it as a
+    disclosure;
+  * and every identity row reads `_sa[0]`/`_la[0]` — **the first charging
+    sample**. At `elapsed = 0` the projection **is** the held level, so the two
+    runs agree **to the float even at a cap that does bind**. Measured:
+    widening the fixture alone — the obvious fix — leaves that comparison
+    passing.
+
+  ⚠️ **THE SECOND REASON IS A NEW SHAPE FOR THIS LIST: AN INDEX, NOT A
+  FIXTURE.** Ask of every identity claim not only *"could this data differ"*
+  but *"**at the point I sampled it**, could it differ yet"*. A comparison
+  taken at `t = 0` between two runs that diverge **because one of them acts**
+  is a comparison of a plant with itself, and no amount of widening the fixture
+  changes that. The replacement, `test_arbitrage.py` part 3d, grades the whole
+  run — 716 of 720 charging cycles differ — and grades the `[0]` agreement **as
+  an expectation**, so nobody rebuilds a check on it believing it covers
+  something.
+
+  ⚠️ **AND THE FIX'S OWN FIRST DRAFT CARRIED A THIRTEENTH.** The new part's
+  action-log check could not reach the log line at all: the sentence was an
+  f-string inside `Controller._shadow_settle()`, and the only suite that drives
+  that method uses a `meter_source: off` fixture where no arbitrage decision —
+  and therefore no caveat — exists. Deleting the caveat from it left **all 29
+  files green**. It is `shadow.log_line()` now. *A sentence assembled at a call
+  site is a sentence no check can grade*, which is CFG-04's substring lesson
+  arriving from the other direction.
+
 Note what these have in common with a masked rung: the mutation *runs*, and the
 suite is *honestly* green. Nothing in a purge, a fingerprint or a disassembly
 can see it, because the code under test really did behave identically on the
@@ -773,6 +811,177 @@ Cheap habits fall out of it, and all of them are now used in this repository:
     retrofitted: guarding another card's section is a change to what its
     checks report, and it belongs to whoever next touches it.
 
+21. ⚠️ **A CHECK CAN BE GREEN UNDER ITS OWN CARD'S NAMED MUTATION, AND TWICE
+    IN ONE FILE THE REASON WAS THAT THE WRONG QUANTITY EVENTUALLY REACHES THE
+    RIGHT VALUE.** TEL-10's acceptance was *"a run that winds the integrator
+    into the bound must show the published number reaching the bound"*, and its
+    named mutation was *"publish `prev_w` instead of `i_w`"*. The check was
+    **GREEN** on the mutant: the command reaches the same bound too, twelve
+    cycles later, and a check that only reads the VALUE cannot tell the two
+    apart. The same file's *"a stopped controller publishes `not-running`"* was
+    green under deleting that branch's assignments outright (−45 B and −67 B),
+    because the fixture STARTED stopped and `__init__` writes the same values.
+    Both are habit 4 - the data could not reach the failure - and both were
+    found by the card's own battery. The fixes are the shape to copy:
+    * where two quantities CONVERGE, grade the **order or the interval**, not
+      the value: "the integrator reaches the bound BEFORE the command does",
+      and a PLATEAU (the lead sits at exactly −800 W for eight consecutive
+      cycles) rather than a maximum, because a maximum is one tick and a
+      plateau is the shape;
+    * where a branch WRITES a value the constructor also writes, the fixture
+      has to pass THROUGH the other state first. Stop the controller part-way
+      through a run that has already wound the integrator to −5000 W, so a row
+      left standing is a WRONG row and not merely an unset one.
+
+22. ⚠️ **AN EXPLANATION IN A COMMENT IS A CLAIM, AND SAFETY-48 SHIPPED TWO THAT
+    WERE INVENTED.** A gate was written one-sided (`if target > slewed: min(...)
+    elif target < slewed: max(...)`) under a comment saying the two-sided band
+    `max(lo, min(hi, i_w))` was a BUG that would drag a trailing integrator
+    toward the command, with a worked example. It is not a bug and the example
+    was wrong: `target` is monotone in `i_w`, so the other clamp cannot reach,
+    and the two spellings agree on **205 920 of 205 920** swept states. A second
+    bullet said two placements of the same cap *"differ on 118 of 256 252
+    ticks"*; that 118 had been measured against a **different pair** and the
+    placement actually being compared is bit-identical on the shipped
+    configuration - 0 of 256 246 ticks. Both sentences were plausible, both were
+    load-bearing for a design choice, and neither had been run.
+    **The rule: a comment that says "X would be wrong" is subject to the same
+    battery as a check - BUILD X AND MEASURE IT.** Where the answer is
+    "equivalent", say so with the sweep size and keep the spelling for what it
+    NAMES; where the answer is a number, quote the run it came from. An
+    invented justification for a correct decision is still a defect, and it is
+    the kind a reviewer cannot see because the code is right.
+
+23. ⚠️ **THE MUTATION IS SUBJECT TO EVERY HABIT ABOVE, HABIT 4 INCLUDED - AND
+    THE PURGE, THE FINGERPRINT AND THE BYTE DELTA ALL SAY IT TOOK.** SAFETY-57's
+    battery reported a **survivor at +21 B** for a mutation of
+    `Freshness._open_window()`: `self.graded_from = float(now_mono)` rewritten
+    as `float(self.changed_mono or now_mono)`, which is meant to re-anchor the
+    verdict's window to the register's own history and so delete the card's
+    whole exit. The harness purged, the tree fingerprint showed the edit on
+    disk, the delta was non-zero, and the mutant really did run. It was still a
+    survivor for a reason that has nothing to do with the property: in the
+    fixture the register never moves after `t = 0`, so `changed_mono` is
+    **`0.0`** - and `0.0 or x` is `x`. **The mutant was a no-op on that
+    stimulus.** Rewritten with an explicit `is None` test (+82 B) it is red on
+    four named checks.
+
+    Stale bytecode is a mutation that never *ran*. This is a mutation that ran
+    and could not *change the answer* on the data it was given, which is habit 4
+    exactly, one level up - and none of the three things a mutation report is
+    required to state (MUTATION.md's own list) can see it, because all three are
+    about the file rather than about the stimulus. Two rules:
+    * **Ask of every survivor what it would have had to change, and check that
+      the fixture reaches that value.** Here: "does any fixture have a non-zero
+      `changed_mono` at the moment `_open_window()` is called?" The answer was
+      no, and it is one line to ask.
+    * **Prefer a mutation that CANNOT be a no-op.** `or`, `and`, truthiness on
+      a numeric, a default argument and a `getattr` fallback all have a value at
+      which the mutant and the shipped tree coincide. An explicit comparison,
+      a constant swap or a deleted statement does not.
+
+    ⚠️ Note where this one was found: in the battery of a card whose whole
+    subject is a check that cannot reach the failure it names. **Second
+    instance in an instrument rather than in a check since habit 16, and the
+    third overall.**
+
+    ⚠️ **AND THE SAME CARD'S BATTERY CAUGHT A HABIT-22 COMMENT IN THE FIX
+    ITSELF, WHICH IS WHY THESE TWO BELONG NEXT TO EACH OTHER.**
+    `freshness.py` shipped `⚠️ RELEASE BEFORE GRADE, AND THE ORDER IS
+    LOAD-BEARING` with a worked reason. Swapping the two calls is **zero bytes**
+    and survived the battery: `_grade()` acts only when `|standing| >= move_w`
+    and `_release()` only when `|standing| < move_w`, so at most one can act on
+    any read and the order is **not observable**. Habit 22 says build X and
+    measure it; the battery is what builds X. The comment now states the
+    disjointness and the suite pins **that** - at 0, 100, 249, 250, 251 and
+    1300 W - rather than an order nothing depends on.
+
+    ⚠️ **SECOND INSTANCE, TEL-11, AND THE NO-OP WAS A SATURATED RAIL RATHER
+    THAN A VALUE.** The card's whole subject is that a PV reading must never
+    reach the control law, so its central mutation is
+    `self.grid = self.grid - self.pv_w` in `read_inputs()` - **+106 B**, on
+    disk, purged, genuinely running - and it came back a **SURVIVOR** of a
+    six-file battery. The property held in no sense: the fixture drove a 6 kW
+    export over 12 cycles, which puts the loop **against its rail**, and a
+    command moving `slew_w` every cycle produces the SAME ramp for -6000 W and
+    for -14000 W of apparent error. The mutant ran and could not change the
+    answer.
+    Two things generalise past PV:
+    * **A SATURATED ACTUATOR IS A VALUE AT WHICH EVERY INPUT COINCIDES.** The
+      habit-23 list above names `or`, `and`, truthiness, default arguments and
+      `getattr` fallbacks - all *expressions* with a coinciding value. A rail,
+      a clamp, a slew limit, a deadband and a latched alarm are the same hazard
+      in the **plant**: they are where a controller's output stops being a
+      function of its input. A fixture that parks there cannot separate any two
+      inputs, and this repository's control fixtures park there by default,
+      because the dramatic stimulus is the saturating one.
+    * **SO THE PRECONDITION IS NOT "DOES IT COMMAND SOMETHING", IT IS "DOES IT
+      REST SOMEWHERE THE MUTATION COULD MOVE IT FROM".** `test_pv.py` part 6
+      now drives a 600 W import the loop SETTLES on, asserts the resting target
+      is well inside the rail, and asks habit 23's own question as a check:
+      shift the METER by the same 8 kW and confirm the commands really would
+      have moved. On the first fixture that question answers NO, in one line,
+      and it is the line that turns the identity into evidence.
+
+24. **A REFUSAL DEFINED RELATIVE TO "THE BASELINE LACKS THIS FEATURE" DIES ON
+    THE RELEASE THAT SHIPS THE FEATURE — AND IT DIES AS A FALSE REFUSAL, WHICH
+    IS THE LOUD DIRECTION.** TEL-11 built `tools/tel11_pv_trace.py` to grade a
+    cross-tree identity, and because "the documents are identical" was its
+    *result* rather than its warning sign, it had to prove instead that the two
+    runs came from different trees and that **exactly one side reacts to
+    `pv_entity`**. That was correct evidence: `release/1.0` predated the option
+    entirely, so a side that reacted to it was the HEAD by construction.
+
+    TEL-11 then **merged**, `release/1.0` became 0.11.0, and the baseline for
+    the next card reacts to `pv_entity` too. `--compare` now answers
+    `REFUSED: set differs from unset on ['A', 'B']` on every honest run — the
+    instrument refuses its own shipped tree. TEL-12 found it on the first
+    comparison it ran.
+
+    * **A discriminator is a fact about a MOMENT, not about a card.** "The
+      baseline does not have X" is true until X ships and then false forever.
+      Write the discriminator against something the NEXT baseline still will not
+      have — TEL-12's is the roster key, not the channel — and say in the tool
+      which fact it rests on, so the next card can see what it has to replace.
+    * **Prefer a discriminator that is MEASURED over one the tree REPORTS.**
+      `tree.supports_roster` is the tree describing itself and would have been
+      one line; the shipped test is "this side's roster cells ARE its unset
+      cells", which is the tree being measured. Both are printed, side by side,
+      so a disagreement between the self-report and the measurement is visible
+      rather than silently trusted.
+    * ⚠️ **And this is the SAFE direction of the same defect, which is why it
+      was found in ten minutes rather than in a review.** A stale refusal is a
+      developer chasing a failure they cannot explain (the false-red case at the
+      top of this file). A stale *identity* — an instrument that goes on printing
+      OK because its reference drifted into agreement — is the survivor-
+      manufacturing direction, and nothing announces it. Ask of every cross-tree
+      instrument: *what does this print when the feature it is about has been in
+      the baseline for a year?*
+
+    TEL-12's own battery produced two more instrument defects of the ordinary
+    kind, both recorded in `DECISIONS/TEL-12-several-pv-inverters.md` §4: a
+    stimulus annotation written into the document being compared (so every cell
+    differed for a reason that was not behaviour, and the discriminator fired on
+    both sides), and a fixture cell whose TRUE total was labelled as its
+    "partial" (so the check refused the shipped tree for publishing a number it
+    is required to publish). ⚠️ **Both were caught by running the instrument
+    against the shipped tree BEFORE running it against a mutant** — which is the
+    one ordering rule that separates "the instrument is wrong" from "the tree is
+    wrong", and `test_mqtt.py` part 8's first line ("the shipped module satisfies
+    every property this instrument grades") is the same rule as a check.
+
+    ⚠️ **AND TEL-12's SUBJECT WAS HABIT 23 IN THE FIXTURE ITSELF.** The card adds
+    a SUM over a roster, and the defect it exists to prevent is publishing the
+    partial sum when a member is absent. A fixture whose absent member
+    contributes **0 W** cannot see that defect at all: the partial and the full
+    total are **the same number**, so "published the absence" and "published the
+    partial" produce identical output. That is a rail in the *arithmetic* rather
+    than in the plant — the same hazard as TEL-11's saturated actuator, one
+    domain over. `test_pv.py`'s roster is three distinct non-zero contributions
+    in two different units, absence is driven at **every position** rather than
+    at one (habit 10), and each position's partial is **computed from the
+    fixture** and asserted to differ from the true total as its own precondition.
+
 And the mutation-table consequence: **a variant is not covered because a
 near-miss of it is.** DEV-02's table listed the *actuator* variant of the
 per-unit claim defect (`device`/`supervised` filed without `inv`), which the
@@ -831,13 +1040,16 @@ document (`'  216.080 ->   0.30123'`), and M13 is red.
 
 **M10 is `+0 B` and it is a real defect, not a synthetic one.** It came out of
 writing the mutation rather than out of review: `implausible_all_in()`'s floor
-was applied to the all-in figure, and `price_taxes_eur_kwh` ships at 0.06 —
+was applied to the all-in figure, and `price_taxes_eur_kwh` shipped at 0.06 —
 **three times the 0.02 floor** — so a card read a hundred times too small
 (0.0016 EUR/kWh of energy) is carried over the floor by the flat tax addend
 alone and passes. The hundredfold error is exactly what that band exists for.
 The floor is applied to the **energy** figure now and the ceiling to the all-in
 one, both directions are graded, and the trap is stated as a check in its own
-right so the asymmetry cannot be "tidied up" later.
+right so the asymmetry cannot be "tidied up" later. *(Annotated 2026-09-13:
+TARIFF-18 raised that default to 0.11736, **nearly six times** the floor. The
+addend that does the carrying got BIGGER, so the trap is wider than when M10
+was measured and the asymmetry is more load-bearing rather than less.)*
 
 **M15 is the one the framework CANNOT catch, and the reds say which half does.**
 Declaring `ALL_IN` makes `assemble()` add nothing, and section 3's all-in check

goodwe_controller/app/allocator.py

@@ -246,11 +246,11 @@ class Allocation:
         block the failsafe is worse than the hole it closes.
         """
         if tick is None or self.tick is None or self.tick != tick:
-            return (f"the allocation record on hand was made on tick "
-                    f"{self.tick!r} and this is tick {tick!r} - a record whose "
-                    f"envelopes have moved cannot authorise a write")
+            return (f"the power split on hand is from tick {self.tick!r}, "
+                    f"not this tick {tick!r}, and an old split cannot allow a "
+                    f"write")
         if not self.ok:
-            return f"the allocator refused this tick ({self.explain()})"
+            return f"no power split was possible this tick ({self.explain()})"
         if unit not in self.shares:
             return (f"{unit} has no share in this tick's allocation "
                     f"({self.explain()})")

goodwe_controller/app/arbiter.py

@@ -226,6 +226,12 @@ CLAIM_SCOPE = {
     # reaches the allocator, so a unit-scoped claim is the shape that sentence
     # asks for rather than an evasion of it.
     "pack": SCOPE_UNIT,
+    # main.py: `Claim.limit("refused", P_SAFETY, ...)` and, during a probe,
+    # `Claim.set("refused", P_SAFETY, +-PROBE_W)`. SAFETY-73: THIS battery gives
+    # nothing in one direction, measured on THIS unit's own reading. A hard unit
+    # limit that always intersects, so the share goes to the siblings. Filed at
+    # N>1 only; at N=1 SAFETY-52's law in compute() does the same job.
+    "refused": SCOPE_UNIT,
     # main.py: `Claim.set("maintenance", P_MAINTENANCE, ...)` when the cycle owns
     # the setpoint, and `Claim.limit("maintenance", P_MAINT_SHAPE, hi=...)` when
     # it only shapes. §12's monthly recalibration is a PACK procedure - drain

goodwe_controller/app/arbitrage.py

@@ -184,6 +184,17 @@ IDLE_OFF_PEAK_HOUR = "this hour is neither the buy hour nor the sell hour"
 IDLE_NO_SIZE = (
     "no pack's state of charge permits this side of the trade, so it is sized "
     "at 0 W - and a 0 W arbitrage claim is a park order, not a trade")
+# SAFETY-45. THE BUY LEG'S SIZE, AND ONLY THE BUY LEG'S - §9.1: "Discharge and
+# export are never capped by the peak guard; only charging and import are."
+IDLE_NO_HEADROOM = (
+    "the capacity-tariff guard has measured this billed quarter and it can "
+    "afford no charging at all, so a trade of any size would push it over the "
+    "ceiling - and a 0 W arbitrage claim is a park order, not a trade")
+IDLE_HEADROOM_UNMEASURED = (
+    "the capacity-tariff guard did not size this quarter's charging headroom "
+    "this cycle, and an UNMEASURED headroom is not an unlimited one - charging "
+    "creates the billed quantity (§9.1) and nothing is measuring the quarter "
+    "this one would land in")
 NEGATIVE_PRICE = (
     "§17: the sell hour is priced BELOW ZERO, so discharging into it would give "
     "energy away and pay for the privilege. Arbitrage must not export at a "
@@ -251,10 +262,8 @@ def threshold_eur_kwh(opts: dict) -> float:
     v = float(price_option(opts, "cycle_cost_threshold_eur"))
     if not math.isfinite(v) or v < 0:
         raise ValueError(
-            f"cycle_cost_threshold_eur is {v!r}. It is what a round trip COSTS, "
-            f"in EUR/kWh, so it is non-negative and finite - a negative "
-            f"threshold is one every spread clears, which is arbitrage with the "
-            f"brake removed.")
+            f"“Battery cycle cost” (cycle_cost_threshold_eur) is {v!r}. Set "
+            f"it to 0 or more, in EUR/kWh.")
     return v
 
 
@@ -303,7 +312,7 @@ def _point_at(plan, when: datetime):
         return None
 
 
-def decide(plan, now: datetime, *, peak_guard_active, soc,
+def decide(plan, now: datetime, *, peak_guard_active, charge_headroom_w, soc,
            min_spread_eur_kwh, uncertainty, charge_w, discharge_w,
            soc_floor_pct, soc_ceiling_pct) -> ArbitrageDecision:
     """Should the battery trade this cycle, and how hard.
@@ -314,6 +323,18 @@ def decide(plan, now: datetime, *, peak_guard_active, soc,
     None refuses, because the alternative is a strategy that creates the billed
     quantity while the thing that would have limited it is switched off.
 
+    ⚠️ `charge_headroom_w` IS SAFETY-45's SECOND, CONTINUOUS ANSWER FROM THE
+    SAME GUARD, AND IT IS NOT A DUPLICATE OF THE FIRST. `peak_guard_active` is a
+    SWITCH - it says whether the guard is holding - and a switch keyed on a
+    continuous quantity is what made the loop oscillate: the guard engaged at a
+    5 W floor, this module refused the whole trade, the loop took the actuator,
+    the meter fell, the guard released and the trade re-armed AT FULL POWER
+    130 s later. 28 times an hour, measured. `peakguard.charge_headroom_w()` is
+    the watts the billed quarter can still afford; sizing the buy leg to it means
+    the trade is CLAMPED rather than switched, which is the same shape
+    `control.maintenance_charge_floor()` has always given a maintenance charge.
+    ⚠️ None IS NOT UNLIMITED here either - see IDLE_HEADROOM_UNMEASURED.
+
     ⚠️ EVERY OTHER ARGUMENT IS KEYWORD-ONLY AND HAS NO DEFAULT, for
     `TariffPlan.arbitrage()`'s reason. A defaulted `soc_floor_pct` is a reserve
     floor this module asserted rather than one the operator configured, and the
@@ -330,10 +351,12 @@ def decide(plan, now: datetime, *, peak_guard_active, soc,
     return verdict.match(
         refused=lambda v: _idle(v.reason),
         allowed=lambda v: _act(plan, now, v, soc, charge_w, discharge_w,
-                               soc_floor_pct, soc_ceiling_pct))
+                               soc_floor_pct, soc_ceiling_pct,
+                               charge_headroom_w))
 
 
-def _act(plan, now, v, soc, charge_w, discharge_w, floor_pct, ceiling_pct):
+def _act(plan, now, v, soc, charge_w, discharge_w, floor_pct, ceiling_pct,
+         headroom_w):
     """The permitted case: which hour is this, and may the pack do it."""
     here = _point_at(plan, now)
     if here is None:
@@ -403,18 +426,110 @@ def _act(plan, now, v, soc, charge_w, discharge_w, floor_pct, ceiling_pct):
             f"nowhere to put the cheap energy", **common)
     if not abs(float(charge_w)) > 0.0:
         return _idle(IDLE_NO_SIZE, **common)
+    # SAFETY-45. THE BILLED QUARTER IS ASKED LAST, AND THE PLACEMENT IS
+    # DELIBERATE: every refusal that existed before this card keeps the
+    # precedence it had, so no sentence an operator already reads changes when
+    # it fires, and the two added here are placed where they cannot displace
+    # one. The pack's reasons come first because they are properties of the
+    # hardware in the cupboard; this one is a property of the fifteen minutes
+    # the trade would land in.
+    if headroom_w is None:
+        # ⚠️ NOT "the guard is clear". This is `guard_state()`'s None argument
+        # one layer down: a headroom nothing measured is not an unlimited one,
+        # and charging at max_w creates the billed quantity (§9.1).
+        return _idle(IDLE_HEADROOM_UNMEASURED, **common)
+    asked_w = abs(float(charge_w))
+    size_w = min(asked_w, max(0.0, float(headroom_w)))
+    if not size_w > 0.0:
+        # ⚠️ NOT IDLE_NO_SIZE, WHICH IS THE LINE ABOVE AND BLAMES THE PACKS.
+        # `asked_w > 0` is already established here, so the pack may be empty
+        # and willing and it is the billed quarter that has run out. A refusal
+        # naming the wrong subsystem sends an operator to the wrong page
+        # (§10.2), and these two are a whole quarter-hour apart in what they
+        # ask a human to do about them.
+        return _idle(IDLE_NO_HEADROOM, **common)
+    # ⚠️ THE SENTENCE CARRIES BOTH NUMBERS IN THEIR OWN SLOTS, not one figure
+    # twice. MUTATION.md habit 14: two values in one sentence can be transposed
+    # by a ZERO-BYTE edit that no byte delta and no shape pin can see, so the
+    # trade's own size and the guard's headroom are each named by the literal
+    # text around them.
+    capped = size_w < asked_w
     return ArbitrageDecision(
-        action=CHARGE, power_w=-abs(float(charge_w)),
+        action=CHARGE, power_w=-size_w,
         reason=(f"{CHARGE}: this is the cheapest firm hour at "
                 f"{price:.4f} EUR/kWh, {v.spread_eur_kwh:.4f} below the dearest "
                 f"and clear of the {v.required_spread_eur_kwh:.4f} this cycle "
-                f"had to cover; charging {abs(float(charge_w)):.0f} W from "
-                f"{soc:g} %"),
+                f"had to cover; charging {size_w:.0f} W from {soc:g} %"
+                + (f" - SIZED BY THE CAPACITY-TARIFF GUARD: the trade asked for "
+                   f"{asked_w:.0f} W and this billed quarter can afford "
+                   f"{float(headroom_w):.0f} W (§9.1, §10.1 priority 2)"
+                   if capped else "")),
         spread_eur_kwh=v.spread_eur_kwh,
         required_eur_kwh=v.required_spread_eur_kwh,
         price_now_eur_kwh=price)
 
 
+def sized_from_meter(decision: ArbitrageDecision, headroom_w, *,
+                     winner: str | None) -> bool:
+    """SAFETY-47. Was the number a shadow run just recorded SIZED FROM THE
+    BILLED QUARTER - i.e. from a measurement of what the battery itself did?
+
+    THE ONE PLACE THIS QUESTION IS ANSWERED, and it is public for the reason
+    `peakguard.charge_headroom_w()`, `discharge_permitted()` and
+    `freeze.looks_frozen()` are: the check that grades it has to assert on THE
+    SHIPPED EXPRESSION. A predicate transcribed into its own test is one copy
+    plus a future disagreement about what the check means.
+
+    ------------------------------------------------------------------------
+    THE DEFECT IT PREVENTS
+
+    `shadow.words()` and the action log carry "would have commanded N W". In
+    SHADOW MODE the battery is held at `shadow.WIRE_W`, so the billed quarter
+    the buy leg was sized against contains THE HOUSE AND NOTHING ELSE - while
+    a live run's meter rises as the trade charges. The same code, the same
+    hour, `peak_cap_w` 1500 under a 1200 W house: live commands -302.4 W and a
+    shadow run records -2000.0 W. 6.61x, on the status row, with no caveat.
+    This is the flag that puts the caveat there.
+
+    ⚠️ IT IS TRUE WHENEVER A MEASURED HEADROOM ENTERED THE ARITHMETIC, NOT
+    ONLY WHEN IT BOUND. `_act()` sizes the buy leg as `min(asked, headroom)`,
+    and "the headroom did not bind" is ITSELF a measured fact about a quarter
+    the battery never entered. Keying this on `capped` - on whether the
+    shipped sentence says "SIZED BY THE CAPACITY-TARIFF GUARD" - would answer
+    True at the START of the quarter, where a shadow run and a live run still
+    agree to the watt, and False at the END, where `(900/remaining)` has
+    multiplied the headroom past the ask and the recorded number is at its
+    most wrong. The quietest caveat exactly where it is needed loudest.
+
+    ⚠️ THE BUY LEG ONLY. §9.1: "Discharge and export are never capped by the
+    peak guard; only charging and import are." A sell is sized from
+    `discharge_w`, which is the roster's own rating and not a measurement of
+    the quarter, so a sell's recorded watts are NOT subject to this and must
+    not carry a caveat that would then be false.
+
+    ⚠️ AND THE ARBITER'S WINNER IS THE THIRD RUNG, NOT AN AFTERTHOUGHT. A trade
+    that was sized from the meter and then OUT-RANKED is not the number being
+    recorded - `Resolution.target_w` belongs to somebody else - and a caveat
+    filed against somebody else's number is a false sentence on the status row,
+    which is the defect class this whole card is about. It is in HERE and not
+    in `main.py` for the reason the two rungs above are: all three answer one
+    question, a check has to be able to reach each of them with the other two
+    clear (TEST-16), and a rung that lives at a call site is a rung no check
+    can drive.
+
+    `headroom_w` is whatever `peakguard.charge_headroom_w()` answered for the
+    cycle this decision was taken on. ⚠️ None IS "NOTHING MEASURED IT", and
+    `decide()` REFUSES the trade there (IDLE_HEADROOM_UNMEASURED), so a None
+    can only ever arrive here beside a non-trading decision - but it is tested
+    rather than assumed, because the caller is `main.py` and not this module.
+
+    `winner` is `Resolution.winner`: the source that actually set the watts.
+    """
+    return (winner == SOURCE
+            and decision is not None and decision.action == CHARGE
+            and headroom_w is not None)
+
+
 def claim(decision: ArbitrageDecision) -> Claim | None:
     """The decision as one arbiter claim, or None when nothing is to be traded.
 

goodwe_controller/app/circulation.py

@@ -325,12 +325,13 @@ class CirculationWatchdog:
             return False
 
         self.tripped = True
+        # UX-10: plain sentences, every figure kept (test_messages.py part 6).
         self.reason = (
             f"CIRCULATING_POWER: {circ_w:.0f} W measured going round between "
-            f"the inverters (peak {self.peak_w:.0f} W) for {held:.0f} s "
-            f"continuously - the meter cannot see it, because it nets to zero "
-            f"there (limits: over {self.cfg.min_w:.0f} W, held over "
-            f"{self.cfg.hold_s:.0f} s)")
+            f"the inverters for {held:.0f} s, peaking at {self.peak_w:.0f} W, "
+            f"over the limits of {self.cfg.min_w:.0f} W and "
+            f"{self.cfg.hold_s:.0f} s. The meter cannot see it, because it "
+            f"nets to zero there")
         return True
 
     def held_s(self, now: datetime) -> float:

goodwe_controller/app/clamp.py

@@ -73,6 +73,7 @@ An alarm wired only to this module's `ClampResult.engaged` would therefore be
 silent on the exact configuration the whole ticket is about. The winding is
 visible one layer up, at the integrator bound, and that is why `Decision` now
 carries `i_clamped` / `clamped` BOOLEANS and the caller ORs them in here.
+They alarm in different words: see `loop_clamp_note()` (SAFETY-40).
 
 AND WHY BOOLEANS RATHER THAN `Decision.reason`. `reason` is a single string that
 later stages overwrite: a cycle that clamps the integrator and is then slew
@@ -141,6 +142,8 @@ import math
 from dataclasses import dataclass
 from datetime import datetime
 
+from . import messages
+
 # The reason code, distinct from any saturation-freeze code by construction:
 # nothing else in this add-on uses it. See "DISTINCT FROM SATURATION".
 REASON_CODE = "OUTPUT_CLAMP"
@@ -200,9 +203,8 @@ REASON_CODE = "OUTPUT_CLAMP"
 # ceiling rests on one number a test author chose; if that number is ever
 # revisited, this constant moves with it.
 #
-# ⚠️ THIS IS A STOP-GAP AND DOES NOT MAKE THE ALARM CORRECT. The message still
-# calls the integrator bound a BUG SIGNAL and still pairs a request from one
-# moment with a `self.target` read at another - SAFETY-40. Nothing here is
+# ⚠️ THIS WAS A STOP-GAP; the wording and the numbers were SAFETY-40's, fixed
+# in `loop_clamp_note()` below. Nothing here is
 # suppressed: every engagement is still counted, the action-log row is written on
 # every engaged cycle regardless, and the rising edge of every episode alarms
 # unconditionally, so no alarm is DROPPED - only delayed.
@@ -234,6 +236,46 @@ CLEAR_CYCLES = 3
 SUSTAINED_CYCLES = 3
 
 
+# UX-10: the reasons below are quoted by a WARNING or ERROR line, so they
+# follow STYLE.md's rule for a quoted reason (test_messages.py part 6): no
+# final full stop, the line adds it. The line around them says "software
+# fault" for an over-rating, so the reason does not. Each is one sentence, so
+# the logged line stays within 3 sentences and about 30 words.
+
+
+def loop_clamp_note(d) -> str:
+    """The loop-side alarm text for one `control.Decision`, or "".
+
+    SAFETY-40: the integrator bound is anti-windup doing its job and says so;
+    only a command over the rating is a software fault. Every number is the
+    decision's own, i.e. from the tick that clamped.
+    """
+    if d.clamped:
+        return (f"{REASON_CODE}: computed {d.requested_w:+.0f} W, cut to the "
+                f"{d.clamped_w:+.0f} W rating, command now {d.target_w:+.0f} W")
+    if d.i_clamped:
+        return (f"{REASON_CODE}: the correction the add-on builds up reached "
+                f"its {d.i_bound_w:+.0f} W limit, command now "
+                f"{d.target_w:+.0f} W")
+    return ""
+
+
+def write_clamp_note(named) -> str:
+    """The write-side alarm text: `named` is `[(inverter name or None,
+    ClampResult)]` for every inverter whose write was cut back this cycle.
+
+    One inverter reads as `describe()`. Several read as one sentence of
+    asked/sent pairs, so the line stays one sentence however many inverters
+    there are. Which limit cut each one back is on its own action-log row
+    (`describe()`) and in the notification."""
+    if len(named) == 1:
+        name, r = named[0]
+        return f"{name}: {r.describe()}" if name else r.describe()
+    return f"{REASON_CODE}: " + ", ".join(
+        f"{name} asked {r.requested_w:+.0f} W and sent {r.applied_w:+.0f} W"
+        for name, r in named)
+
+
 @dataclass(frozen=True)
 class ClampResult:
     """What the guard did, with the RAW value preserved.
@@ -250,10 +292,12 @@ class ClampResult:
     bound: str = ""          # "" | "max_w" | "device" - which stage bit
 
     def describe(self) -> str:
-        return (f"{REASON_CODE}: the computed setpoint {self.requested_w:+.0f} W "
-                f"was clamped to {self.applied_w:+.0f} W by the {self.bound} "
-                f"bound (rating {self.limit_w:.0f} W) - something upstream is "
-                f"winding")
+        # The sent value IS the limit that bound, so the rating is not
+        # repeated: on "max_w" it equals the rating, and on "device" the
+        # rating was not what cut it back.
+        return (f"{REASON_CODE}: asked {self.requested_w:+.0f} W and sent "
+                f"{self.applied_w:+.0f} W, "
+                f"{messages.LIMIT_WORDS.get(self.bound, self.bound)}")
 
 
 def is_commandable(value) -> bool:
@@ -333,32 +377,72 @@ class ClampWatchdog:
     def __init__(self):
         self.active = False
         self.engagements = 0      # every engagement, never deduplicated
+        # UX-08: the same count split by alarm type, so the status page names
+        # each with its own alarm's title after the episode clears.
+        self.over_rating = 0      # bug=True: "Power request too high"
+        self.bound = 0            # bug=False: "Battery is not keeping up"
         self.episodes = 0         # rising edges
         self.since: datetime | None = None
         self.last_alarm: datetime | None = None
         self.reason = ""
+        # UX-08: the numbers behind `reason`, for the notification - set under
+        # the same rule as `reason`, so both always describe the same tick.
+        self.facts = ()
         self.clean_cycles = 0
         # SAFETY-41. Consecutive engaged cycles, and whether THIS episode has
         # spoken yet - the two the escalation clause needs.
         self.run_len = 0
         self.spoken = False
+        # SAFETY-40. Did this episode include a genuine over-rating (`bug`), and
+        # has THAT spoken? A bug has its own budget, so anti-windup notices can
+        # never delay it; with bug=True throughout, cadence is as before.
+        self.bug = False
+        self.bug_spoken = False
+        self.last_bug_alarm: datetime | None = None
 
-    def note(self, engaged: bool, reason: str, now: datetime) -> bool:
+    def _due(self, last, now) -> bool:
+        return last is None or (now - last).total_seconds() >= REASSERT_S
+
+    def _speak(self, now, bug) -> bool:
+        self.last_alarm = now
+        self.spoken = True
+        if bug:
+            self.last_bug_alarm = now
+            self.bug_spoken = True
+        return True
+
+    def note(self, engaged: bool, reason: str, now: datetime,
+             bug: bool = True, facts=()) -> bool:
         """Advance one cycle. True when the caller should raise the alarm.
 
         `now` is the caller's clock, the same discipline as
-        `SignWatchdog.evaluate()` and `FreezeWatchdog.evaluate()`.
+        `SignWatchdog.evaluate()` and `FreezeWatchdog.evaluate()`. `bug` False
+        is the integrator bound (SAFETY-40): counted and notified like the
+        rest, but it never replaces a bug's text within an episode.
         """
         if engaged:
             self.engagements += 1
+            if bug:
+                self.over_rating += 1
+            else:
+                self.bound += 1
             self.clean_cycles = 0
-            self.reason = reason
             self.run_len += 1
-            if not self.active:
+            rising = not self.active
+            if rising:
                 self.active = True
                 self.since = now
                 self.episodes += 1
                 self.spoken = False
+                self.bug = False
+                self.bug_spoken = False
+            if bug or not self.bug:
+                self.reason = reason
+                self.facts = tuple(facts)
+            self.bug = self.bug or bug
+            if bug and not self.bug_spoken and self._due(self.last_bug_alarm, now):
+                return self._speak(now, True)
+            if rising:
                 # ⚠️ SAFETY-41. THE RISING EDGE IS RATE-LIMITED TOO, and it did
                 # not used to be. It fired unconditionally, so a condition that
                 # engages and clears repeatedly raised one notification PER
@@ -384,11 +468,8 @@ class ClampWatchdog:
                 # still written on every engaged cycle, and a genuine runaway -
                 # which by definition keeps engaging - is picked up by the
                 # re-assert path within REASSERT_S. Delay, not loss.
-                if (self.last_alarm is None
-                        or (now - self.last_alarm).total_seconds() >= REASSERT_S):
-                    self.last_alarm = now
-                    self.spoken = True
-                    return True
+                if self._due(self.last_alarm, now):
+                    return self._speak(now, self.bug)
                 return False
             # ⚠️ THE ESCALATION. An episode that has not yet spoken because the
             # budget was spent by an EARLIER, unrelated episode speaks anyway
@@ -396,15 +477,10 @@ class ClampWatchdog:
             # engages every cycle and reaches it; the scattered one-cycle
             # railing that produced the live flood never does.
             if not self.spoken and self.run_len >= SUSTAINED_CYCLES:
-                self.last_alarm = now
-                self.spoken = True
-                return True
+                return self._speak(now, self.bug)
             # Still engaged: re-assert on the slow cadence, not every cycle.
-            if (self.last_alarm is None
-                    or (now - self.last_alarm).total_seconds() >= REASSERT_S):
-                self.last_alarm = now
-                self.spoken = True
-                return True
+            if self._due(self.last_alarm, now):
+                return self._speak(now, self.bug)
             return False
 
         self.run_len = 0
@@ -420,5 +496,7 @@ class ClampWatchdog:
             # above. The episode ends; the notification budget does not reset
             # with it.
             self.reason = ""
+            self.facts = ()
+            self.bug = False
             self.clean_cycles = 0
         return False

goodwe_controller/app/config_page.py

@@ -413,10 +413,9 @@ function showProblems(payload){
   save.disabled = total > 0;
   if(total){
     note(banner, 'bad', 'This configuration would not start.',
-      'The add-on refuses to run on it and would stop with exit 78. '
-      + 'Saving is blocked until these are fixed; nothing has been written. '
-      + 'Each message below is the add-on\\u2019s own words, from the same '
-      + 'check that runs at startup.');
+      'The add-on would refuse to start on it. Saving is blocked until these '
+      + 'are fixed, and nothing has been written. Each message below comes '
+      + 'from the same check that runs at start.');
     banner.insertBefore(banner.lastChild, banner.firstChild);
     msg(total + (total === 1 ? ' problem' : ' problems')
         + ' - saving is blocked', 'bad');

goodwe_controller/app/configui.py

@@ -289,7 +289,10 @@ def problems_by_field(problems, keys):
     cross-field rule is about all of its fields, and hiding it from one of them
     would be this card's own defect in miniature.
     """
-    patterns = [(key, re.compile(r"(?<![A-Za-z0-9_])" + re.escape(key)
+    # ⚠️ `.` BEFORE THE KEY DOES NOT COUNT (UX-08 2d): `inverters.max_w`
+    # names a setting of one inverter in the list, which is changed under
+    # `inverters`, and it must not also land beside the flat `max_w`.
+    patterns = [(key, re.compile(r"(?<![A-Za-z0-9_.])" + re.escape(key)
                                  + r"(?![A-Za-z0-9_])")) for key in keys]
     by_key, unanchored = {}, []
     for problem in problems:

goodwe_controller/app/control.py

@@ -191,6 +191,108 @@ SETTLE_CYCLES = math.ceil(PLANT_SETTLE_DOWN_S / LOOP_TICK_S)  # 12
 # edge rather than in prose, because it is a property of two files agreeing.
 _SAT_COUNT_CAP = SETTLE_CYCLES + 1                           # 13
 
+# ---------------------------------------------------------------------------
+# SAFETY-48. HOW FAR THE INTEGRATOR MAY STAND AHEAD OF THE COMMAND.
+#
+# ⚠️ THE MISSING CASE, AND IT IS A CASE AND NOT A CONSTANT. The freeze below
+# stops the integrator accumulating, and the comment beside it says what the
+# requirement is: "the INTEGRATOR stop accumulating, not only the command". But
+# `frozen` is computed from ONE signal - `abs(prev_w - actual_w) >
+# saturation_w`, the inverter not tracking - and SLEW-LIMITING NEVER ENTERS IT.
+# When the command hits the step ceiling, the integrator goes on winding at
+# `gain * error` until it reaches `integrator_max_w`.
+#
+# The arithmetic, and it is the whole card:
+#
+#     the integrator moves   gain * error   per cycle
+#     the command moves at most      slew   per cycle
+#     so the integrator outruns the command whenever
+#
+#         |error|  >  slew / gain
+#
+# At the live install's shape (gain 0.6, slew_w 400) that is 667 W. The median
+# grid error at the onset of a recorded episode is 1114 W. This is why
+# SAFETY-39's `slew_w` retune did not fix it: a smaller step makes the
+# threshold LOWER, so the case fires more often, not less.
+#
+# ⚠️ WHAT IS BOUNDED IS THE LEAD, NOT THE INTEGRATOR. Two forms were measured
+# over 16.0 days of the live install's own recorded disturbances
+# (`tools/replay_recorded_loop.py`, and DECISIONS/SAFETY-48 has the table):
+#
+#   (a) reuse the asymmetric freeze on a carried slew flag - "may not wind
+#       further in the direction it is already pushing", exactly as saturation
+#       does. It cuts export 13 % AND RAISES THE BILLED QUANTITY: the worst
+#       quarter-hour average OFFTAKE goes 3739 -> 3935 W and the mean quarter
+#       moves +2.7 W, in five of six plant and tuning variants, and on the
+#       billed quarter it is worse at every plant lag where release/1.0
+#       produces a peak at all (a tie at lag 0, worse at 2.5/5/7.5/10 s)
+#       and at every top-N cut of the quarters.
+#
+#       ⚠️ AND THE MECHANISM IS A REDISTRIBUTION, NOT A WEAKER ANSWER. An
+#       earlier draft of this line said a frozen integrator undershoots by
+#       (1 - gain) "so a large import is answered too weakly". The aggregate
+#       does not show that: form A cuts total import by 5.45 kWh, and paired
+#       tick by tick against release/1.0 it delivers 8.56 kWh LESS offtake
+#       energy on the ticks release/1.0 was importing. What it moves is the
+#       TAIL - within quarters that already net to offtake, the worst of them
+#       gets worse - and the capacity tariff bills the worst quarter and
+#       nothing else. That is the wrong trade here and the reason this is not
+#       the fix that ships.
+#
+#   (b) cap how far the integrator may LEAD the command, one slew step. Export
+#       39.6 -> 34.1 kWh, wasted throughput 4.7 -> 3.2 kWh, sign reversals
+#       2992 -> 2770, worst quarter-hour offtake 3739 -> 3434 W at the fitted
+#       plant lag (⚠️ AND AT NO SHORTER ONE: at every lag <= 5.0 s release/1.0
+#       is already at 3434 W and this changes it by zero - DECISIONS/SAFETY-48
+#       §3a), median recovery 232 -> 199 s. It is what ships.
+#
+# ⚠️ AND THE CAP IS NOT ZERO. `i_w = slewed` is full back-calculation, and this
+# module's own docstring says what that costs: passing `i_w=None` "reduces this
+# function to the exact velocity form it replaced". A zero cap makes `i_w`
+# identically the command on every cycle, which is that same collapse written
+# from the other end - it measures 32.0 kWh, better than (b) by 2 kWh, and it
+# throws away the reason the accumulator was split out at all. One step is the
+# smallest cap that is not that.
+#
+# WHAT THE NUMBER MEANS: the command can cover a one-step lead in ONE cycle, so
+# the worst-case unwind after a reversal is one cycle instead of
+# `integrator_max_w / slew_w` - 12.5 cycles at the live shape, ~60 s at the
+# meter's measured 5.0 s tick.
+#
+# ⚠️ IT IS IN STEPS RATHER THAN IN WATTS FOR SAFETY-39's REASON, WHICH IS THE
+# REASON THIS FILE KEEPS RE-LEARNING. A watt figure is a constant that outlives
+# the `slew_w` it was derived against; expressed in steps it moves with
+# `slew_limit_w()` and therefore with the rail.
+SLEW_LEAD_STEPS = 1
+
+# ---------------------------------------------------------------------------
+# SAFETY-52. A BATTERY THAT REFUSES IS ASKED FOR 0 W, NOT HELD AT ITS LAST ASK.
+#
+# At the BMS cut-out the pack delivers ~0 W whatever it is asked, so the
+# saturation freeze below holds the command where it stood (the recorded
+# 09-06 case: +5000 W for 11.87 h) until the grid error changes sign. The
+# freeze's own exit cannot help: a reading of ~0 against a large ask is inside
+# the interval a limit can produce. So a refused DIRECTION is held at 0 W,
+# carried between cycles like `sat_count`, and left again when the loop wants
+# the other direction, when a small probe is answered, or when the caller
+# resets it (stop, start, another writer). The record is DECISIONS/SAFETY-52.
+#
+# PROBE_W is below freshness.MOVE_W (250 W) on purpose: a probe that small can
+# never arm the stale-reading gate, so it cannot start the gate's ~70 s cycle.
+# test_refusal.py pins the inequality. The cadence and length are the owner's
+# 2026-09-27 answer (every 15 minutes) and freshness.BATT_OBLIGED_S twice over
+# (17 s is how long a healthy reading needs to show a command).
+REFUSED = "battery refuses"
+PROBING = "battery probe"
+PROBE_W = 200.0
+PROBE_ANSWER_W = PROBE_W / 2
+# "Gives nothing" is below the probe's own answer, not below `saturation_w`: a
+# pack derated to 100-499 W is a limit, and at 500 W it kept ~7 % of its power
+# (review of #141). The capture's refusals read -4 W.
+REFUSED_BELOW_W = PROBE_ANSWER_W
+PROBE_EVERY_S = 900.0
+PROBE_S = 34.0
+
 
 @dataclass(frozen=True)
 class Tuning:
@@ -266,6 +368,15 @@ class Decision:
     # the comment at the bound below, and clamp.py.
     i_clamped: bool = False
     clamped: bool = False
+    # SAFETY-40. The alarm's numbers, taken at the clamp so they are one tick's:
+    # the bound the integrator reached, and the command before/after the
+    # rating clamp. `target_w` is this tick's emitted command.
+    i_bound_w: float = 0.0
+    requested_w: float = 0.0
+    clamped_w: float = 0.0
+    # SAFETY-52. The refused direction to carry back in (+1 discharge, -1
+    # charge, 0 none), or None when the caller does not carry it.
+    refused: int | None = None
 
 
 def slew_limit_w(tuning: Tuning) -> float:
@@ -362,6 +473,8 @@ def compute(
     tuning: Tuning,
     sat_count: int = 0,
     i_w: float | None = None,
+    refused: int | None = None,
+    probe: bool = False,
 ) -> Decision:
     """One control cycle. A cycle is one meter update (~5 s on a HomeWizard P1).
 
@@ -369,6 +482,9 @@ def compute(
     `grid_w`   net grid power, + = importing
     `actual_w` what the inverter reports it is doing, + = discharging
     `i_w`      the carried integrator, or None to seed it from `prev_w`
+    `refused`  SAFETY-52's carried refused direction, or None to leave it out
+               (the `i_w=None` equivalence path does)
+    `probe`    the caller's clock says a refused direction may try PROBE_W now
     """
     reason = "tracking"
 
@@ -489,6 +605,7 @@ def compute(
         # winding, "clamped" is a command that came out over the rating anyway.
         reason = "i-clamped"
     i_w = bounded
+    i_bound_w = bounded if i_clamped else 0.0
     want = i_w
 
     # ⚠️ Maintenance shaping (charge-only, cheap-window floor) used to live
@@ -500,6 +617,7 @@ def compute(
     # An early draft applied a floor after the clamp and let demand escape it.
     target = max(-tuning.max_w, min(tuning.max_w, want))
     clamped = target != want
+    clamped_w = target
     if clamped:
         reason = "clamped"
 
@@ -507,6 +625,83 @@ def compute(
     slewed = max(prev_w - slew, min(prev_w + slew, target))
     if slewed != target:
         reason = "slew-limited"
+        # --- SAFETY-48: the step ceiling reaches the integrator too ---------
+        # ⚠️ INSIDE THIS BRANCH AND NOWHERE ELSE - AND THE REASON IS NOT THE
+        # SATURATION FREEZE. An earlier draft of this comment said that applied
+        # unconditionally the cap "would also pull the integrator toward a
+        # command the SATURATION freeze is pinning", and priced that at 118 of
+        # 256 250 ticks. Both halves were invented, and MUTATION.md habit 22 is
+        # what fell out of it. The 118 had been measured against a DIFFERENT
+        # pair - a band applied after quantisation, at the very end of
+        # `compute()`. On the pair the sentence actually names - this same cap
+        # moved out of this branch to just after `target = slewed` - the two
+        # forms are BIT-IDENTICAL on the shipped configuration: 0 of 256 246
+        # ticks differ over the 16-day recording. They separate only where
+        # `integrator_max_w` is deliberately set ABOVE `max_w`, the one
+        # configuration this file says can reach its `clamped` reason; there
+        # the integrator is meant to run above the rail and an unconditional
+        # cap would drag it back to the command every cycle and make the option
+        # inert. THAT is why the cap stays in the branch, and
+        # `test_telemetry.py` part 4 drives it. (The separable-state COUNT is a
+        # property of whatever grid was swept - 2050 of 257 400 on this card's,
+        # 1220 of 246 064 on the review's, 776 of 40 320 on a third - so the
+        # claim to carry forward is WHERE they separate, not how many.)
+        #
+        # ⚠️ AND THE HALF A READER WILL OTHERWISE ASSUME AWAY: THIS CAP DOES
+        # MOVE A SATURATION-FROZEN INTEGRATOR. It runs BEFORE the freeze block
+        # below and is not gated on `frozen`. Measured over the same recording
+        # at the live shape: of 79 160 frozen ticks the cap changed `i_w` on
+        # 1095 of them, and on 679 of those it moved it FURTHER OUT on the side
+        # it was already on - putting back magnitude the freeze had just let
+        # fall, which is the one direction the freeze's own rule ("may fall,
+        # never rise") exists to forbid. Worst case 2424 W, and the worked tick
+        # is `prev_w -3400 W, grid +4697 W, actual -4144 W, sat_count 2 -> 3`:
+        # the freeze leaves the integrator at -176 W, the slew binds, and the
+        # cap drags it to -2600 W. It never overrides a SAME-CYCLE refusal -
+        # the freeze clipped `moved` on 75 512 ticks and the slew bound on none
+        # of them - but it does not leave the frozen path alone either.
+        #
+        # ⚠️ AND THAT IS WHERE SAFETY-13's SETTLE VALUES WENT. Gating this cap
+        # on `not frozen` puts `test_control.py` part 5 back at release/1.0's
+        # -1190 W exactly; part 4(b)'s -2390 -> -1200 W does NOT come back,
+        # because that one moved for the other reason - the winding BEFORE the
+        # freeze is bounded now. The gate is refused anyway: measured the same
+        # way it leaves a worst observed lead of 4961 W, i.e. no bound at all
+        # on the quantity this card exists to bound. DECISIONS/SAFETY-48 §5
+        # carries the rest of the price.
+        #
+        # ⚠️ WRITTEN ONE-SIDED, AND IT IS **EQUIVALENT** TO THE TWO-SIDED BAND
+        # `max(slewed - cap, min(slewed + cap, i_w))` - MEASURED, NOT REASONED.
+        # An earlier draft of this comment claimed the two-sided spelling was a
+        # bug that would drag a TRAILING integrator up toward the command. That
+        # is false and the sweep said so: `target` is monotone in `i_w`
+        # (`target = clamp(clamp(i_w, +-limit), +-max_w)`) and `slewed` is
+        # `target` pulled toward `prev_w`, so whenever the slew binds, `i_w`
+        # lies on the same side of `slewed` as `target` does and the other
+        # clamp cannot reach. The two spellings agree on **205 920 of 205 920**
+        # cases across four tunings, every sign of `prev_w`, `grid_w`,
+        # `actual_w` and `i_w`, and the `i_w=None` path.
+        #
+        # It stays one-sided because it SAYS which side the lead is on - the
+        # side the command wanted to move and could not - and because a reader
+        # reaching for the band spelling should find the sweep rather than an
+        # argument. ⚠️ The "descending" case is NOT an exception to the rule: a
+        # command falling from +2400 W toward an integrator at +100 W has an
+        # integrator 2300 W ahead of it IN THE DIRECTION OF TRAVEL, and it is
+        # pulled back to one step beyond the emitted command exactly as a
+        # rising one is.
+        #
+        # ⚠️ `i_w` IS CHANGED AND `target` IS NOT. This cycle's command is
+        # already decided; what is bounded is what gets CARRIED. That is also
+        # why the exhaustive `i_w=None` equivalence sweep in test_control.py is
+        # untouched by this card: it compares `(target_w, sat_count, frozen,
+        # reason)`, none of which this moves, and the seeded path re-seeds from
+        # `prev_w` next cycle anyway.
+        _lead_cap = SLEW_LEAD_STEPS * slew
+        if target > slewed:
+            i_w = min(i_w, slewed + _lead_cap)
+        elif target < slewed:
+            i_w = max(i_w, slewed - _lead_cap)
     target = slewed
 
     if frozen:
@@ -580,6 +775,27 @@ def compute(
             target = min(target, prev_w) if prev_w > 0 else max(target, prev_w)
             reason = "saturated-freeze"
 
+    # --- SAFETY-52: a refused direction is held at 0 W ----------------------
+    # Engages only where the freeze has held for SETTLE_CYCLES and the unit
+    # delivers ~nothing: a reading below REFUSED_BELOW_W against an ask beyond
+    # `saturation_w` is a refusal, not a slow plant. The drop to 0 skips the slew
+    # limit because it only removes an ask the battery is not meeting.
+    if refused is not None:
+        if (refused == 0 and frozen and sat_count >= SETTLE_CYCLES
+                and abs(prev_w) > tuning.saturation_w
+                and abs(actual_w) < REFUSED_BELOW_W):
+            refused = 1 if prev_w > 0 else -1
+        if refused and refused * i_w < 0:
+            refused = 0                          # the loop wants the other way
+        elif refused and refused * actual_w >= PROBE_ANSWER_W:
+            refused = 0                          # it delivers: a probe answered,
+            #                                     or a slow reading arriving
+        elif refused:
+            wants = refused * i_w > 0
+            i_w = 0.0
+            target = refused * PROBE_W if probe and wants else 0.0
+            reason = PROBING if probe and wants else REFUSED
+
     # --- quantise ----------------------------------------------------------
     # 10 W. The register is 1 W and the inverter reports at 1 W, but its
     # response lands on a coarser ladder (~17.6 W measured at ~900 W, consistent
@@ -589,7 +805,8 @@ def compute(
     target = round(target / step) * step
 
     return Decision(float(target), sat_count, frozen, reason, float(i_w),
-                    i_clamped, clamped)
+                    i_clamped, clamped, float(i_bound_w), float(want),
+                    float(clamped_w), refused)
 
 
 def maintenance_charge_floor(

goodwe_controller/app/custom_formula.py

@@ -125,6 +125,49 @@ units and the market aggregator prints both conventions in one column, so the
 add-on has to be told which one the card is in - and the unit conversion is the
 add-on's job precisely because it is one of the two steps that silently costs a
 factor of 10, 100 or 1000. The other is VAT, which is also the add-on's.
+
+TARIFF-16 - THE SECOND LEG, AND WHY IT IS THIS PARSER AND NOT A SECOND ONE
+==========================================================================
+A Belgian dynamic contract has TWO published lines, not one, and the second is
+what the site is PAID for export:
+
+    Eneco Zon & Wind Dynamisch   0,1 x BELPEX-H - 1,188   c EUR/kWh
+    ENGIE Dynamic                (B x eSpot_15) - A
+    Aspiravi (non-dynamic)       0,07 x Belpex - 2
+
+Same `B x index + A` shape - which is why `price_export_formula` is this
+module's parser with ONE argument moved (`option`), exactly as TARIFF-17 made
+`parse_static_profile()`'s option name a parameter rather than forking the
+period grammar. What differs between the two legs is FOUR numbers and a
+handful of sentences, and all of them are rows of `_LEGS`:
+
+  * its OWN factor - Eneco 0,102 on consumption against 0,100 on injection,
+    Aspiravi 0,07 against ~0,10. NOT the consumption `B` with a sign flip;
+  * a NEGATIVE offset, which `factor`/`offset` already allow and which
+    `price_markup_eur_kwh: float(0,1)` cannot express at all;
+  * `vat_pct: 0` - "Injectietarieven zijn vrijgesteld van btw" - against 6 on
+    consumption, which is a SIX PERCENT ASYMMETRY between the buy leg and the
+    sell leg and is representable only because `vat_pct` is PER SPEC;
+  * a price that goes BELOW ZERO with no floor, in the hours a PV household
+    exports. `implausible_injection()` is the band that accepts that and still
+    refuses an implausible one; `implausible_all_in()` is NOT it, and its
+    docstring says why.
+
+⚠️ AND THE CARD CANNOT ALWAYS GRADE IT. Eneco's injection formula is printed
+with NO price beside it, so on that card there is nothing to reproduce. The
+`card` block is therefore OPTIONAL on this leg and REQUIRED on the other, the
+self-check runs wherever there is a printed estimate, and validate.py says at
+startup when a leg is ungraded. Inventing an estimate to grade against would
+be grading arithmetic against itself, which is the defect MUTATION.md habit 4
+is about; TARIFF-15 demonstrated two tariffs end to end rather than three for
+the same reason.
+
+⚠️ NOTHING TRADES ON THIS TODAY, AND SAYING SO IS PART OF SHIPPING IT.
+`arbitrage.py` does not read `export_price_eur_kwh` at all - its own comment
+says so, citing §9.3's near-zero Belgian injection price - and both hours it
+compares are all-in CONSUMPTION prices. So this is not a wrong-trade defect
+and must not be described as one. What it changes is what an operator is told,
+and what a future export-aware strategy would rest on.
 """
 
 import json
@@ -132,6 +175,8 @@ import math
 from dataclasses import dataclass
 from datetime import date, datetime, timezone
 
+from . import messages
+
 
 class FormulaInvalid(Exception):
     """`price_formula` cannot be used. Raised by the parser, refused by
@@ -156,7 +201,7 @@ RESOLUTIONS: tuple = ("hourly", "quarter_hourly")
 # index id -> the human name of the series it refers to. One entry today; a
 # second index is a new row here plus a fetch path, not a new grammar.
 INDEXES: dict = {
-    "epex_be": "EPEX BE day-ahead, EUR/MWh",
+    "epex_be": "Belgian day-ahead price, EUR/MWh",
 }
 
 # ⚠️ 0.01 IN THE CARD'S OWN UNITS, WHICH IS THE LAST DIGIT BOTH REAL CARDS
@@ -183,6 +228,91 @@ _CARD_KEYS = ("month", "index_eur_per_mwh", "expect_incl_vat")
 _TOP_KEYS = ("index", "resolution", "factor", "offset", "units", "vat_pct",
              "card")
 
+# --------------------------------------------------------------------------- #
+# TARIFF-16 - the SECOND leg, and the one parameter that carries it
+# --------------------------------------------------------------------------- #
+
+EXPORT_FORMULA_OPTION = "price_export_formula"
+
+# ⚠️ THE PASS-THROUGH FRACTION, WHICH IS WHY THE NEXT TWO BOUNDS CAN BE
+# INDEX-FREE. One EUR/MWh IS 0.001 EUR/kWh, so `factor x UNITS[units] / 0.001`
+# is the dimensionless share of the wholesale price the contract passes
+# through - 1.00 for Eneco's injection leg (0,100 c EUR/kWh per EUR/MWh), 0.70
+# for Aspiravi's (0,07). A coefficient typed a hundred times too small or too
+# large moves this by a hundred, whatever the index and whatever the sign of
+# the price.
+EUR_KWH_PER_EUR_MWH = 0.001
+
+# The two plausibility bounds for an INJECTION leg. ⚠️ NEITHER LOOKS AT THE
+# SIGN OF THE PRICE, AND THAT IS THE WHOLE POINT - see
+# `implausible_injection()`.
+PASSTHROUGH_LO = 0.10       # 10% of the wholesale price
+PASSTHROUGH_HI = 10.0       # 1000% of it
+INJECTION_OFFSET_MAX_EUR_KWH = 0.20
+
+
+@dataclass(frozen=True)
+class _Leg:
+    """What ONE option's coefficients price, as sentences its refusals read.
+
+    ⚠️ TARIFF-16 MADE `option` A PARAMETER RATHER THAN FORKING THE PARSER,
+    exactly as TARIFF-17 made `option`/`means` parameters of
+    `parse_static_profile()` rather than forking the period grammar. A second
+    copy of this parser would be a second `_finite()`, a second unknown-key
+    rule, a second unit table and a second `to_resolution()` - and the two
+    would diverge first on the 23- and 25-hour days, where nobody looks.
+    Everything that differs between the consumption leg and the injection leg
+    is a STRING in this table; the arithmetic, the enumerations, the card
+    comparison and the resolution rule are ONE implementation with one set of
+    checks over it.
+    """
+
+    option: str
+    what: str            # "consumption" / "injection", for a sentence
+    example: str         # a VALID blob for this leg, in the JSON-error hint
+    when: str            # when this option is read at all
+    flat: str            # where a FLAT price of this kind already lives
+    zero_factor: str     # what a factor of 0 actually costs on this leg
+    neg_factor: str      # why a negative FACTOR is wrong on this leg
+    card_required: bool
+    card_note: str       # why it is required, or what is lost without it
+    card_causes: str     # the leg-specific tail of `card_refusal()`
+
+
+_LEGS = {
+    "price_formula": _Leg(
+        option="price_formula",
+        what="consumption",
+        example=('{"index":"epex_be","resolution":"hourly","factor":0.102,'
+                 '"offset":1.00,"units":"c_eur_per_kwh","vat_pct":6,'
+                 '"card":{"month":"2026-09","index_eur_per_mwh":133.9905,'
+                 '"expect_incl_vat":15.55}}'),
+        when="Leave it empty unless “Dynamic price source” is 'custom_formula'.",
+        zero_factor=" and trading never finds a price difference",
+        flat="use “Fixed or day/night tariff” (static_profile) instead",
+        neg_factor="Put the minus sign on the offset, not on the factor",
+        card_required=True,
+        card_note="The add-on needs it to check your two numbers",
+        card_causes=("the units, the VAT, and that network charges are not "
+                     "in the offset"),
+    ),
+    EXPORT_FORMULA_OPTION: _Leg(
+        option=EXPORT_FORMULA_OPTION,
+        what="injection",
+        example=('{"index":"epex_be","resolution":"hourly","factor":0.1,'
+                 '"offset":-1.188,"units":"c_eur_per_kwh","vat_pct":0}'),
+        when="Fill it in only if your injection price follows the market.",
+        zero_factor="",
+        flat="use “Injection price” (export_price_eur_kwh) instead",
+        neg_factor="Put the minus sign on the offset, not on the factor",
+        card_required=False,
+        card_note=("It is optional here. Without it the add-on only checks "
+                   "the size of your two numbers"),
+        card_causes="the units, and that the VAT is 0 for injection",
+    ),
+}
+
+
 
 @dataclass(frozen=True)
 class FormulaSpec:
@@ -199,14 +329,44 @@ class FormulaSpec:
     offset: float
     units: str
     vat_pct: float
-    card_month: str                 # "YYYY-MM", as the card is dated
-    card_index_eur_per_mwh: float
-    card_expect_incl_vat: float     # in `units`, as the card prints it
+    card_month: str = ""            # "YYYY-MM", as the card is dated
+    card_index_eur_per_mwh: float = None
+    card_expect_incl_vat: float = None   # in `units`, as the card prints it
+    # TARIFF-16. Which OPTION this spec was read from, so a refusal, a log line
+    # and `card_graded` name the leg the operator actually typed.
+    option: str = "price_formula"
 
     @property
     def unit_to_eur_kwh(self) -> float:
         return UNITS[self.units]
 
+    @property
+    def card_graded(self) -> bool:
+        """Is there a printed estimate to grade these coefficients against?
+
+        ⚠️ FALSE IS A REAL, SHIPPED STATE ON THE INJECTION LEG and is reported
+        rather than defaulted: Eneco's injection formula is printed with no
+        price beside it. Never False on `price_formula`, where `_card()`
+        refuses an absent block.
+        """
+        return self.card_expect_incl_vat is not None
+
+    @property
+    def passthrough(self) -> float:
+        """The dimensionless share of the wholesale price this passes through.
+
+        `factor x UNITS[units] / 0.001`. 1.00 for Eneco's injection leg, 0.70
+        for Aspiravi's. ⚠️ INDEX-FREE AND SIGN-FREE, which is what lets
+        `implausible_injection()` bound a leg whose price legitimately goes
+        below zero.
+        """
+        return self.factor * self.unit_to_eur_kwh / EUR_KWH_PER_EUR_MWH
+
+    @property
+    def offset_eur_kwh(self) -> float:
+        """The offset in EUR/kWh, whatever units the card printed it in."""
+        return self.offset * self.unit_to_eur_kwh
+
 
 # --------------------------------------------------------------------------- #
 # The arithmetic. Two functions, and the SECOND one is the contract.
@@ -241,7 +401,18 @@ def card_discrepancy(spec: FormulaSpec) -> float:
     In the card's units, signed: positive means the formula computes MORE than
     the card prints, which is the direction an `offset` carrying network
     charges moves it.
+
+    ⚠️ RAISES ON A SPEC WITH NO CARD RATHER THAN RETURNING 0.0 (TARIFF-16). An
+    ungraded injection leg has no printed estimate, and a discrepancy of zero
+    is exactly what "the coefficients reproduce the card" looks like - so a
+    silent zero here would report the strongest possible result for the one
+    state in which nothing was compared at all.
     """
+    if not spec.card_graded:
+        raise FormulaInvalid(
+            f"{spec.option} has no card block, so there is no printed "
+            f"estimate to measure a discrepancy against. Ask "
+            f"`spec.card_graded` before calling this.")
     return in_card_units(spec, spec.card_index_eur_per_mwh) \
         - spec.card_expect_incl_vat
 
@@ -250,7 +421,7 @@ def card_discrepancy(spec: FormulaSpec) -> float:
 # Reading the option
 # --------------------------------------------------------------------------- #
 
-def _finite(value, field: str) -> float:
+def _finite(value, field: str, option: str = "price_formula") -> float:
     """A real, finite number - or a refusal naming the field.
 
     ⚠️ SAME CLASS AS `_validate_raw()`'s NaN RULE, one layer earlier. A NaN
@@ -260,51 +431,54 @@ def _finite(value, field: str) -> float:
     """
     if isinstance(value, bool) or not isinstance(value, (int, float)):
         raise FormulaInvalid(
-            f"price_formula.{field} is {value!r}, which is not a number. "
-            f"Write the coefficient as a bare JSON number - 0.102, not "
-            f"\"0.102\" and not an expression: this provider takes FIXED "
-            f"coefficients and evaluates nothing.")
+            f"{option}.{field} is {value!r}, which is not a number. Write a "
+            f"plain number, for example 0.102.")
     if not math.isfinite(float(value)):
         raise FormulaInvalid(
-            f"price_formula.{field} is {value!r}, which is not finite. A NaN "
-            f"or an infinity here makes every price NaN, every price "
-            f"comparison False, and an arbitrage strategy that never fires "
-            f"while reporting that it is armed.")
+            f"{option}.{field} is {value!r}, which is not finite. Write a "
+            f"plain number, for example 0.102.")
     return float(value)
 
 
-def _card(raw) -> tuple:
-    """The `card` block: the estimate the coefficients are graded against."""
+def _card(raw, leg: _Leg = None) -> tuple:
+    """The `card` block: the estimate the coefficients are graded against.
+
+    ⚠️ REQUIRED ON THE CONSUMPTION LEG AND OPTIONAL ON THE INJECTION ONE, and
+    the asymmetry is a fact about the CARDS rather than a relaxed rule. See
+    `_LEGS[EXPORT_FORMULA_OPTION].card_note`: Eneco's injection formula is
+    printed with no price beside it, so on that card there is nothing to grade
+    against. `("", None, None)` is the ungraded answer and
+    `FormulaSpec.card_graded` is how every caller asks.
+    """
+    if leg is None:
+        leg = _LEGS["price_formula"]
     if raw is None:
+        if not leg.card_required:
+            return ("", None, None)
         raise FormulaInvalid(
-            "price_formula has no \"card\" block, and it is REQUIRED. It is "
-            "the only thing that can tell a correct pair of coefficients from "
-            "a plausible-looking wrong one: the add-on recomputes your "
-            "supplier's own printed example from the numbers you typed and "
-            "refuses to start if it does not come out. Copy the three figures "
-            "off the same tariff card as the coefficients: "
+            f"{leg.option} has no \"card\" block. {leg.card_note}. Copy "
+            "the three figures from your tariff card, for example "
             "{\"month\": \"2026-09\", \"index_eur_per_mwh\": 133.9905, "
             "\"expect_incl_vat\": 15.55}.")
     if not isinstance(raw, dict):
         raise FormulaInvalid(
-            f"price_formula.card is {type(raw).__name__}, not an object with "
+            f"{leg.option}.card is {type(raw).__name__}, not an object with "
             f"{', '.join(_CARD_KEYS)}.")
     unknown = sorted(set(raw) - set(_CARD_KEYS))
     if unknown:
         raise FormulaInvalid(
-            f"price_formula.card has no field(s) {unknown}. The fields it "
-            f"takes are {list(_CARD_KEYS)}; a key that is merely ignored is a "
-            f"number the operator believes took effect.")
+            f"{leg.option}.card has unknown field(s) {unknown}. It takes "
+            f"only {list(_CARD_KEYS)}.")
     month = str(raw.get("month", "") or "").strip()
     if not _month_date(month):
         raise FormulaInvalid(
-            f"price_formula.card.month is {raw.get('month')!r}; write the "
-            f"month the card is dated as \"YYYY-MM\", e.g. \"2026-09\". It is "
-            f"not used in any price - it is what lets the add-on tell you "
-            f"your card has gone stale.")
+            f"{leg.option}.card.month is {raw.get('month')!r}. Write the "
+            f"month of the card as \"YYYY-MM\", for example \"2026-09\".")
     return (month,
-            _finite(raw.get("index_eur_per_mwh"), "card.index_eur_per_mwh"),
-            _finite(raw.get("expect_incl_vat"), "card.expect_incl_vat"))
+            _finite(raw.get("index_eur_per_mwh"), "card.index_eur_per_mwh",
+                    leg.option),
+            _finite(raw.get("expect_incl_vat"), "card.expect_incl_vat",
+                    leg.option))
 
 
 def _month_date(month: str):
@@ -316,9 +490,16 @@ def _month_date(month: str):
         return None
 
 
-def parse_price_formula(value):
+def parse_price_formula(value, *, option: str = "price_formula"):
     """`price_formula` -> a `FormulaSpec`, or None when unset.
 
+    ⚠️ `option` IS TARIFF-16'S WHOLE REUSE, and it is TARIFF-17's move. It
+    selects a row of `_LEGS` and nothing else: the enumerations, the
+    arithmetic, `to_resolution()`, the unknown-key rule and the card
+    comparison are shared, and every pre-existing call site - which passes no
+    `option` at all - lands on the consumption row and reads byte-identical
+    sentences. `parse_export_formula()` is a two-line wrapper, not a fork.
+
     Accepts what the option can actually arrive as, exactly as
     `parse_static_profile()` does:
 
@@ -335,6 +516,7 @@ def parse_price_formula(value):
     fetch - go through this one function, so there is no route to a price that
     has not been graded against the card.
     """
+    leg = _LEGS[option]
     if value is None:
         return None
     if isinstance(value, str):
@@ -345,16 +527,11 @@ def parse_price_formula(value):
             value = json.loads(text)
         except ValueError as e:
             raise FormulaInvalid(
-                f"price_formula is not valid JSON ({e}). It is a JSON object "
-                f"on one line, e.g.\n"
-                f'  {{"index":"epex_be","resolution":"hourly","factor":0.102,'
-                f'"offset":1.00,"units":"c_eur_per_kwh","vat_pct":6,'
-                f'"card":{{"month":"2026-09","index_eur_per_mwh":133.9905,'
-                f'"expect_incl_vat":15.55}}}}\n'
-                f"Leave it empty unless price_provider is 'custom_formula'.")
+                f"{messages.not_valid(option, e)}. Copy the example from the "
+                f"documentation. {leg.when}")
     if not isinstance(value, dict):
         raise FormulaInvalid(
-            f"price_formula is {type(value).__name__}, not a JSON object with "
+            f"{option} is {type(value).__name__}, not a JSON object with "
             f"{', '.join(_TOP_KEYS)}.")
 
     # ⚠️ AN UNKNOWN KEY IS REFUSED, NOT IGNORED, AND THIS IS THE HALF THAT
@@ -366,34 +543,21 @@ def parse_price_formula(value):
     unknown = sorted(set(value) - set(_TOP_KEYS))
     if unknown:
         raise FormulaInvalid(
-            f"price_formula has no field(s) {unknown}. The fields it takes "
-            f"are {list(_TOP_KEYS)}. ⚠️ There is deliberately NO field that "
-            f"takes an expression: this provider multiplies and adds two "
-            f"FIXED coefficients and evaluates nothing, because two "
-            f"coefficients can be graded against your card's printed price "
-            f"and an arbitrary expression cannot be graded against anything. "
-            f"If your contract needs a shape this cannot express, it needs a "
-            f"new named field here - say which shape.")
+            f"{option} has unknown field(s) {unknown}. It takes only "
+            f"{list(_TOP_KEYS)}.")
 
     index = str(value.get("index", "") or "").strip()
     if index not in INDEXES:
         raise FormulaInvalid(
-            f"price_formula.index is {value.get('index')!r}. The reference "
-            f"series this add-on can fetch are "
-            f"{', '.join(f'{k!r} ({v})' for k, v in sorted(INDEXES.items()))}. "
-            f"If your card names a different index, the add-on cannot get it "
-            f"and guessing which series your supplier meant would price your "
-            f"battery against the wrong curve.")
+            f"{option}.index is {value.get('index')!r}. The add-on can only "
+            f"fetch "
+            f"{', '.join(f'{k!r} ({v})' for k, v in sorted(INDEXES.items()))}.")
 
     resolution = str(value.get("resolution", "") or "").strip()
     if resolution not in RESOLUTIONS:
         raise FormulaInvalid(
-            f"price_formula.resolution is {value.get('resolution')!r}; it "
-            f"must be one of {list(RESOLUTIONS)}. Belgium has been on a "
-            f"15-minute MTU since 2025-10-01 and the feed publishes 96 points "
-            f"a day; a contract written against the HOURLY series is priced "
-            f"on the mean of each hour's quarters. Which one your contract "
-            f"uses is on your card and cannot be inferred from the feed.")
+            f"{option}.resolution is {value.get('resolution')!r}. Choose one "
+            f"of {list(RESOLUTIONS)}, as your tariff card says.")
 
     # ⚠️ `units` IS REQUIRED AND HAS NO DEFAULT. A default here would be the
     # factor-1000 class with a friendly face: the add-on would silently assume
@@ -402,16 +566,12 @@ def parse_price_formula(value):
     units = str(value.get("units", "") or "").strip()
     if units not in UNITS:
         raise FormulaInvalid(
-            f"price_formula.units is {value.get('units')!r} and is REQUIRED - "
-            f"there is no default, on purpose. It must be one of "
-            f"{sorted(UNITS)}. Your card prints the formula in ONE of these "
-            f"and two suppliers use two different conventions for the same "
-            f"shape, so assuming one would be a factor of 100 or 1000 on "
-            f"every hour with nothing able to notice.")
+            f"{option}.units is {value.get('units')!r}. Choose one of "
+            f"{sorted(UNITS)}, as printed beside the formula on your card.")
 
-    factor = _finite(value.get("factor"), "factor")
-    offset = _finite(value.get("offset"), "offset")
-    vat_pct = _finite(value.get("vat_pct"), "vat_pct")
+    factor = _finite(value.get("factor"), "factor", option)
+    offset = _finite(value.get("offset"), "offset", option)
+    vat_pct = _finite(value.get("vat_pct"), "vat_pct", option)
 
     # ⚠️ ZERO IS NOT "NO INDEXATION", IT IS A FIXED TARIFF WEARING A DYNAMIC
     # ONE'S CLOTHES. Every hour comes out at the same price, so every spread is
@@ -421,15 +581,8 @@ def parse_price_formula(value):
     # the operator at it rather than let them build it by accident.
     if factor == 0.0:
         raise FormulaInvalid(
-            "price_formula.factor is 0, so the index would not enter the "
-            "price at all: every hour of every day comes out at "
-            f"{offset:g} x (1 + {vat_pct:g}/100), every spread is exactly 0, "
-            "and arbitrage can never clear any threshold - a strategy that "
-            "silently never fires rather than one that is off. If your tariff "
-            "really is one flat price, that is `static_profile` with a single "
-            "period covering 00:00-24:00 on all days and price_provider "
-            "'off'; the add-on then says so at startup instead of leaving you "
-            "to find out from a year of unchanged bills.")
+            f"{option}.factor is 0, so every hour gets the same {leg.what} "
+            f"price{leg.zero_factor}. For one flat price, {leg.flat}.")
 
     # ⚠️ A NEGATIVE FACTOR INVERTS THE MARKET, and the direction is the danger:
     # the dearest hour becomes the cheapest one, so the battery is told to
@@ -437,74 +590,102 @@ def parse_price_formula(value):
     # mispriced site, it is a site actively trading against itself.
     if factor < 0.0:
         raise FormulaInvalid(
-            f"price_formula.factor is {factor:g}, which is NEGATIVE. That "
-            f"inverts the market: the dearest hour of the day comes out as "
-            f"the cheapest one, so the battery would charge at the evening "
-            f"peak and discharge at 03:00 - trading against itself on every "
-            f"cycle. No consumption tariff is indexed negatively; if your "
-            f"card shows a minus sign it is on the OFFSET (`A`), which is "
-            f"allowed here and common on injection.")
+            f"{option}.factor is {factor:g}, which turns the market upside "
+            f"down. {leg.neg_factor}.")
 
     # ⚠️ 0 IS LEGITIMATE AND MUST STAY SO: injection is VAT-exempt in Belgium,
     # and some cards are already quoted VAT-inclusive. The bound exists for the
     # 106 / 1.06 / 6 confusion, not to make VAT compulsory.
     if not 0.0 <= vat_pct <= 30.0:
         raise FormulaInvalid(
-            f"price_formula.vat_pct is {vat_pct:g} and must be between 0 and "
-            f"30. It is a PERCENTAGE, so Belgian residential electricity is "
-            f"6, not 0.06 and not 106. Zero is legitimate and is not refused: "
-            f"injection is VAT-exempt, and a card that already quotes "
-            f"VAT-inclusive coefficients needs no second multiplication.")
+            f"{option}.vat_pct is {vat_pct:g}. Write a percentage between 0 "
+            f"and 30, for example 6.")
 
-    month, card_index, card_expect = _card(value.get("card"))
+    month, card_index, card_expect = _card(value.get("card"), leg)
     spec = FormulaSpec(index=index, resolution=resolution, factor=factor,
                        offset=offset, units=units, vat_pct=vat_pct,
                        card_month=month, card_index_eur_per_mwh=card_index,
-                       card_expect_incl_vat=card_expect)
+                       card_expect_incl_vat=card_expect, option=option)
 
-    delta = card_discrepancy(spec)
-    if abs(delta) > CARD_TOLERANCE:
-        raise FormulaInvalid(card_refusal(spec, delta))
+    # ⚠️ THE CARD SELF-CHECK STILL RUNS WHEREVER THERE IS A CARD TO RUN IT
+    # AGAINST, on either leg, with the same tolerance. What TARIFF-16 adds is
+    # the honest answer for the leg where the card prints no estimate: NOT a
+    # weakened comparison and NOT an estimate computed here, but two bounds on
+    # the COEFFICIENTS that need no printed price - see
+    # `implausible_injection()` - and a startup line saying the leg is
+    # ungraded.
+    if spec.card_graded:
+        delta = card_discrepancy(spec)
+        if abs(delta) > CARD_TOLERANCE:
+            raise FormulaInvalid(card_refusal(spec, delta))
+    if option == EXPORT_FORMULA_OPTION:
+        band = implausible_injection(spec)
+        if band:
+            raise FormulaInvalid(band)
     return spec
 
 
+def parse_export_formula(value):
+    """`price_export_formula` -> the INJECTION leg's `FormulaSpec`, or None.
+
+    TARIFF-16. THE DEFECT THIS EXISTS TO CLOSE: `price.py` modelled injection
+    as ONE scalar, and the market publishes a line with four properties a
+    scalar cannot hold. Verbatim off the cards:
+
+        Eneco Zon & Wind Dynamisch   0,1 x BELPEX-H - 1,188   c EUR/kWh
+            "Het injectietarief is dynamisch en kan per uur wijzigen"
+            - identical on the January and the September 2026 cards
+        ENGIE Dynamic                (B x eSpot_15) - A       c EUR/kWh
+        Aspiravi (non-dynamic)       0,07 x Belpex - 2
+
+      1. ITS OWN FACTOR. Eneco uses 0,102 on consumption and 0,100 on
+         injection; Aspiravi 0,07 against ~0,10 on its consumption leg. It is
+         NOT the consumption `B` with a sign flip.
+      2. A NEGATIVE OFFSET - `- 1,188`, `- 2`. Note that
+         `price_markup_eur_kwh: float(0,1)` cannot express a negative markup
+         at all, so the offset has no home on the consumption side either.
+      3. VAT-EXEMPT. "Injectietarieven zijn vrijgesteld van btw", while
+         consumption is at 6% - a SIX PERCENT ASYMMETRY between the buy leg
+         and the sell leg, which a single scalar cannot even state.
+      4. IT GOES NEGATIVE, WITH NO FLOOR. Eneco's injection price is negative
+         for any BELPEX-H below 11,88 EUR/MWh, and a PV household exports
+         precisely in the hours most likely to be negative. You can be charged
+         to export.
+
+    ⚠️ AND WHAT THIS DOES **NOT** AFFECT TODAY, SAID HERE SO NOBODY READS THE
+    ABOVE AS A TRADING BUG. `arbitrage.py` does not read
+    `export_price_eur_kwh` at all - its own comment says so, and gives §9.3's
+    near-zero Belgian injection price as the reason the economically sound
+    trade on this market is charge-cheap-to-displace-expensive-IMPORT. Both
+    hours it compares are all-in CONSUMPTION prices. So no trade the add-on
+    takes today is decided by this number, and this card is not a correction
+    of a wrong trade. What it changes is what an operator is told, and what
+    any future export-aware strategy would rest on: OPT-06 and any export
+    logic would otherwise inherit a scalar that cannot represent the market,
+    and the 6% VAT asymmetry would be invisible in the arithmetic.
+
+    ⚠️ THE SCALAR IS NOT REPLACED. `export_price_eur_kwh()` is untouched and
+    still answers for every site with a flat injection price, which is every
+    site that exists today; this option ships "". That is `price.py`'s own
+    prediction coming true rather than a new design - "when it does land, an
+    injection curve gets a `PriceProvider` of its own and this scalar becomes
+    its FIXED-product default; the seam is already the right shape for that."
+    """
+    return parse_price_formula(value, option=EXPORT_FORMULA_OPTION)
+
+
 def card_refusal(spec: FormulaSpec, delta: float) -> str:
     """The sentence an operator reads when their formula misses its own card.
 
-    ⚠️ IT NAMES THE DISCREPANCY AND THE SIX WAYS IT HAPPENS. "Invalid
-    configuration" would be true and useless: every one of these errors looks
-    exactly like a working tariff from the status page, which is why the check
-    exists at all.
+    It names both numbers and what to check. The usual causes are in DOCS.md,
+    because each of these errors looks like a working tariff on the status page.
     """
     got = in_card_units(spec, spec.card_index_eur_per_mwh)
-    ratio = (got / spec.card_expect_incl_vat
-             if spec.card_expect_incl_vat else float("inf"))
+    leg = _LEGS[spec.option]
     return (
-        f"price_formula does not reproduce its own card, so the add-on will "
-        f"NOT start on it. Your contract's arithmetic is "
-        f"price = (factor x index_eur_per_mwh + offset) x (1 + vat_pct/100); "
-        f"on the card's own index that is "
-        f"({spec.factor:g} x {spec.card_index_eur_per_mwh:g} + "
-        f"{spec.offset:g}) x (1 + {spec.vat_pct:g}/100) = {got:.4f} "
-        f"{spec.units}, but card.expect_incl_vat says "
-        f"{spec.card_expect_incl_vat:g} - OUT BY {delta:+.4f} {spec.units} "
-        f"(ratio {ratio:.4g}; the tolerance is {CARD_TOLERANCE}, which is the "
-        f"last digit a card prints). One of the two sides is wrong and the "
-        f"add-on cannot tell which, so it refuses rather than price a battery "
-        f"on it. The usual causes, in the order they happen: the coefficients "
-        f"and the expected price are in DIFFERENT units (ratio 10, 100 or "
-        f"1000 - `units` must be the one the formula line is printed in); VAT "
-        f"left out or applied twice (ratio 1.06 or 1/1.06); a transposed "
-        f"digit; the two sides copied off DIFFERENT cards or different "
-        f"months; or - the expensive one - network charges, levies or excise "
-        f"folded into `offset`. ⚠️ THEY DO NOT BELONG THERE: a Belgian card's "
-        f"Tariefformule line is the ENERGY component alone (Eneco tabulates "
-        f"network tariffs and levies separately; ENGIE says in so many words "
-        f"that the formula excludes network, distribution, transport, levies "
-        f"and excise), the add-on adds price_taxes_eur_kwh on top of it, and "
-        f"folding ~12 c EUR/kWh of network charge into `offset` bills you for "
-        f"it twice. That is the error this check exists to catch, and it is "
-        f"why it cannot be switched off.")
+        f"{spec.option} gives {got:.4f} "
+        f"{messages.UNIT_WORDS.get(spec.units, spec.units)}, the card says "
+        f"{spec.card_expect_incl_vat:g}. Check {leg.card_causes}.")
 
 
 # --------------------------------------------------------------------------- #
@@ -520,13 +701,16 @@ def implausible_all_in(spec: FormulaSpec, taxes_eur_kwh: float):
 
     ⚠️ THE LOW END IS GRADED ON THE ENERGY COMPONENT AND THE HIGH END ON THE
     ALL-IN FIGURE, AND THAT ASYMMETRY IS THE CHECK RATHER THAN AN OVERSIGHT.
-    `price_taxes_eur_kwh` ships at 0.06, which is three times the low bound -
-    so a card read a HUNDRED times too small comes out at 0.0016 EUR/kWh of
-    energy, is carried over the floor by the flat tax addend alone, and passes
-    a band applied to the all-in total. The hundredfold error is precisely
-    what this exists to catch, so the floor is applied where it can still see
-    it. The ceiling is applied to the all-in figure because that is the number
-    the site is really billed at, and taxes only push it up.
+    `price_taxes_eur_kwh` ships at 0.11736 (TARIFF-18; it was 0.06 before, and
+    the argument was already decisive at that figure), which is nearly SIX
+    times the low bound - so a card read a HUNDRED times too small comes out at
+    0.0016 EUR/kWh of energy, is carried over the floor by the flat tax addend
+    alone, and passes a band applied to the all-in total. The hundredfold error
+    is precisely what this exists to catch, so the floor is applied where it
+    can still see it. ⚠️ Raising the default made this trap WIDER, not
+    narrower: the addend that does the carrying got bigger. The ceiling is
+    applied to the all-in figure because that is the number the site is really
+    billed at, and taxes only push it up.
 
     ⚠️ AND THE LIMIT, WITH THE CLAIM. This grades the CARD'S OWN POINT - one
     price, at the monthly index the card assumed - and not every hour of every
@@ -536,26 +720,89 @@ def implausible_all_in(spec: FormulaSpec, taxes_eur_kwh: float):
     fetched series. What it catches is a formula whose whole LEVEL is wrong,
     which is the factor-of-1000 class arriving from the end
     `MAX_PLAUSIBLE_EUR_KWH` does not bound.
+
+    ⚠️ AND IT IS THE CONSUMPTION LEG'S BAND ONLY - TARIFF-16 DELIBERATELY DID
+    NOT POINT IT AT THE INJECTION LEG. Two reasons, and the second is an
+    acceptance criterion rather than a preference:
+
+      * it adds `taxes_eur_kwh`, and `price_taxes_eur_kwh` is a CONSUMPTION
+        component. Nothing is added to what a site is PAID for export, so the
+        `all_in` half would be adding a number the injection leg never carries;
+      * its floor is `energy >= 0.02 EUR/kWh`, and a REAL Eneco injection price
+        is negative for any BELPEX-H below 11,88 EUR/MWh - the hours a PV
+        household actually exports in. Applied to injection this floor would
+        refuse the market, and refuse it hardest in the hours where knowing the
+        number matters most. `implausible_injection()` is the injection band
+        and it is deliberately NOT this function with a lower floor.
     """
     energy = price_eur_kwh(spec, spec.card_index_eur_per_mwh)
     all_in = energy + float(taxes_eur_kwh)
     if energy >= PLAUSIBLE_LO_EUR_KWH and all_in <= PLAUSIBLE_HI_EUR_KWH:
         return None
     return (
-        f"price_formula's own card works out at {energy:.5f} EUR/kWh of "
-        f"energy ({spec.card_expect_incl_vat:g} {spec.units} as the card "
-        f"prints it) and {all_in:.5f} EUR/kWh all-in once "
-        f"price_taxes_eur_kwh is added, which is outside the plausible band "
-        f"{PLAUSIBLE_LO_EUR_KWH}-{PLAUSIBLE_HI_EUR_KWH} EUR/kWh for a Belgian "
-        f"retail tariff. The card self-check passed, so the coefficients and "
-        f"the printed price AGREE - they simply agree on a number no Belgian "
-        f"bill carries, which is what a whole card read in the wrong units "
-        f"looks like (a factor of 10, 100 or 1000 applied to BOTH sides at "
-        f"once cancels out of that check and cannot cancel out of this one). "
-        f"Check `units` against the unit printed beside your formula. "
-        f"⚠️ This bounds the CARD'S OWN POINT, not every hour: a live hour may "
-        f"legitimately fall outside the band, and a negative day-ahead hour - "
-        f"the best charging opportunity of the year - is never refused.")
+        f"{spec.option} gives {energy:.5f} EUR/kWh for energy and "
+        f"{all_in:.5f} EUR/kWh with “Distribution, levies and VAT” "
+        f"(price_taxes_eur_kwh), outside the plausible band of "
+        f"{PLAUSIBLE_LO_EUR_KWH}-{PLAUSIBLE_HI_EUR_KWH} EUR/kWh. Check \"units\" against the unit beside your formula.")
+
+
+def implausible_injection(spec: FormulaSpec):
+    """The INJECTION leg's plausibility band. Returns a refusal or None.
+
+    ⚠️ A NEGATIVE INJECTION PRICE IS ACCEPTED, NOT REFUSED, AND NEITHER RUNG
+    BELOW LOOKS AT THE SIGN OR THE LEVEL OF A PRICE. Eneco's published line
+    `0,1 x BELPEX-H - 1,188` is negative for any BELPEX-H under 11,88 EUR/MWh;
+    those are the midday hours a PV household exports in, so a band with a
+    floor above zero - which is what `implausible_all_in()` has, for the
+    consumption leg's own good reasons - would refuse the real market and
+    would hide it in exactly the hours it costs money. You CAN be charged to
+    export. The add-on says so rather than declining to represent it.
+
+    THE PROBLEM THAT LEAVES, STATED BEFORE THE SOLUTION. The consumption
+    floor was not decoration: it is what catches a whole card read a hundred
+    times too small, the one unit error the card self-check cannot see because
+    it cancels out of a comparison between the two sides. A band that spans
+    zero cannot catch it - 0.00132 EUR/kWh is inside any interval that
+    contains -0.03. So the bound moves OFF the price and ONTO the
+    coefficients, where it is index-free and sign-free:
+
+      * PASS-THROUGH. `factor x UNITS[units] / 0.001` is the dimensionless
+        share of the wholesale price the contract passes through, because one
+        EUR/MWh IS 0.001 EUR/kWh. Eneco's injection leg is 1.00 and Aspiravi's
+        is 0.70. A factor typed 100x too small reads 0.01 and 100x too large
+        reads 100, whatever the index and whatever the sign of the result.
+      * OFFSET MAGNITUDE. Eneco's is 1,188 c EUR/kWh = 0.01188 EUR/kWh and
+        Aspiravi's is 2 c = 0.02. A hundredfold error is 1.188 EUR/kWh, which
+        is not an injection tariff in any direction. The bound is on the
+        ABSOLUTE value, so a negative offset of a believable size passes and
+        that is the normal case on this leg.
+
+    ⚠️ TWO RUNGS THAT CAN BOTH ANSWER ONE STIMULUS, SO THEY ARE GRADED ON
+    THEIR REASONS AND MUTATED TOGETHER (MUTATION.md, TEST-16). A whole card
+    read 100x too large trips both. The fixtures in test_price.py 17d are
+    built so that each rung is the ONLY one that fires on its own stimulus.
+
+    ⚠️ AND WHAT THIS CANNOT SEE, WITH THE CLAIM (habit 13). It bounds the
+    SHAPE of the coefficients, never their truth: a contract really written
+    against a different index, or last year's coefficients, passes both rungs
+    and reproduces any card typed beside them. Where a card DOES print an
+    estimate the self-check grades the pair against it; where it does not -
+    which is Eneco's injection line - these two bounds are the whole of what
+    is mechanised, and validate.py says so at startup.
+    """
+    if not PASSTHROUGH_LO <= spec.passthrough <= PASSTHROUGH_HI:
+        return (
+            f"{spec.option}.factor passes through {spec.passthrough:.4g}x the "
+            f"market price, outside {PASSTHROUGH_LO}-{PASSTHROUGH_HI}x. Check "
+            f"\"units\" ({spec.units!r}) against the unit beside your "
+            f"formula.")
+    if abs(spec.offset_eur_kwh) > INJECTION_OFFSET_MAX_EUR_KWH:
+        return (
+            f"{spec.option}.offset is {spec.offset:g} {spec.units}, which is "
+            f"{spec.offset_eur_kwh:+.5f} EUR/kWh and larger than "
+            f"{INJECTION_OFFSET_MAX_EUR_KWH} EUR/kWh either way. Check its "
+            f"unit.")
+    return None
 
 
 def stale_card(spec: FormulaSpec, today=None):
@@ -568,15 +815,9 @@ def stale_card(spec: FormulaSpec, today=None):
     if dated is None or (now - dated).days <= CARD_STALE_DAYS:
         return None
     return (
-        f"price_formula's card is dated {spec.card_month}, which is "
-        f"{(now - dated).days} days ago. Suppliers reprice: if your contract "
-        f"has been renewed or rolled over since then, the coefficients here "
-        f"are last year's and every price this add-on computes is wrong by "
-        f"however far they moved - and the card self-check cannot see it, "
-        f"because it grades your coefficients against the card you typed, not "
-        f"the card against your current contract. Not refused: ENGIE freezes "
-        f"coefficients for the contract's duration, so an old card is often "
-        f"exactly right. Worth re-reading your klantenzone once.")
+        f"{spec.option}'s card is dated {spec.card_month}, "
+        f"{(now - dated).days} days ago. The add-on still starts, but if your "
+        f"contract changed since, copy the new figures from your supplier.")
 
 
 # --------------------------------------------------------------------------- #

goodwe_controller/app/freeze.py

@@ -424,15 +424,17 @@ class FreezeWatchdog:
         # page was telling, printed into the log and the HA notification where
         # it would outlive the page.
         ceiling = rail_ceiling_w(max_w, dev_min=dev_min, dev_max=dev_max)
+        # UX-10: plain sentences, every figure kept (test_messages.py part 6).
         capped = ("" if ceiling >= abs(float(max_w))
                   else f", capped from max_w {float(max_w):.0f} W by the "
-                       f"setpoint device's own rating")
+                       f"inverter's own rating")
         self.reason = (
-            f"METER_FROZEN: the meter has answered {float(unchanged_s):.0f} s "
-            f"without its measurement changing while the command stands at "
-            f"{float(commanded_w):+.0f} W, at the {ceiling:.0f} W rail{capped} "
-            f"(limits: unchanged over {self.cfg.hold_s:.0f} s, command over "
-            f"{rail_w(max_w, dev_min=dev_min, dev_max=dev_max):.0f} W)")
+            f"METER_FROZEN: the meter has not changed for "
+            f"{float(unchanged_s):.0f} s while the command is "
+            f"{float(commanded_w):+.0f} W, at the {ceiling:.0f} W limit"
+            f"{capped}. Limits: unchanged over {self.cfg.hold_s:.0f} s, "
+            f"command over "
+            f"{rail_w(max_w, dev_min=dev_min, dev_max=dev_max):.0f} W")
         if self.active:
             return False
         self.active = True

goodwe_controller/app/freshness.py

@@ -175,6 +175,124 @@ only one of them is WIRED - see `BOUNDS` below and the note on SoC.
   integrator, and K. It does NOT owe a second freshness mechanism - `Freshness`
   below takes its obligation term from the caller precisely so that an energy
   integral can be handed in where command travel is handed in here.
+
+
+THE EXIT, AND WHY THE FIRST VERSION OF THIS MODULE DID NOT HAVE ONE (SAFETY-57)
+==============================================================================
+⚠️ THE VERDICT ABOVE IS ABOUT AN OBLIGATION, AND ITS OWN CONSEQUENCE REMOVES
+THE OBLIGATION. Declaring the reading stale makes `Controller.inputs_ok` False,
+which commands 0 W (§11.1 rule 1). At 0 W nothing is asking the register to be
+anywhere - `|standing| >= MOVE_W` is false, so the conjunction cannot arm - and
+the class docstring's clearing rule, "an arrival carrying a DIFFERENT number",
+asks the register for evidence that only a command could have produced. A pack
+sitting at its BMS floor answers the same integer watt for hours. **The state
+had no exit reachable from inside it**, and the operator-facing line said the
+opposite: *"It clears itself the moment the register reports a different
+value."*
+
+MEASURED ON THE LIVE SITE, 2026-09-21, and committed as
+`scenarios/safety57-2026-09-21/` - a passive RS-485 capture, decoded by
+`tools/decode_bus_capture.py`:
+
+    10:51:24.7   0x0518 reaches -3 W. The pack is at 11 % and the loop has just
+                 reversed from -447 W of charge into discharge; the BMS refuses
+                 and the inverter idles. The register is HEALTHY and TRUTHFUL.
+    10:51:29.7   the standing command reaches +1060 W. 800 W of travel, and the
+                 register is obliged to follow it.
+    10:52:00     the conjunction arms. `Inverter.batt` becomes None.
+    10:52:21.7   the site commands 0 W - on the wire, in the capture.
+    ...          0x0518 does not change value for 850.0 s. The setpoint does not
+                 change value for 790.0 s. Nothing in this add-on can end it.
+    11:04        a human restarts the add-on.
+    11:05:31.7   the restarted loop commands -400 W of charge, which the pack
+                 ACCEPTS at 11 %, and the register moves 3 s later.
+
+⚠️ AND IT HAD BEEN ESCAPING BY LUCK. This BMS emits a keep-alive pulse of a few
+hundred watts, which twitches 0x0518 and satisfies the clearing rule by
+accident. Replaying the committed 16-day loop capture
+(`scenarios/loop-2026-09-02_2026-09-17/`) through the shipped conjunction at
+1 Hz gives **93 trips**, and the time from each trip to the register's next
+change - which was the ONLY exit - has a median of 143 s, 17 episodes at or
+over the live one's 710 s, and a worst case of 21440 s. That distribution is a
+property of this battery's firmware. It is not a property of this code, and the
+add-on must not depend on it.
+
+THE RULE, and it is SAFETY-13's shape one module over - "which latches get an
+exit, not how long the block lasts":
+
+    RELEASE  <=>  the verdict is standing
+                  AND |standing command| < MOVE_W has held continuously for
+                      >= RELEASE_S
+
+On a release the latch clears and a NEW grading window opens at that instant:
+the register is re-graded, from scratch, against the commands issued AFTER it.
+Nothing about the register's own history is rewritten - `changed_mono`,
+`held` and `unchanged_s()` go on reporting that the register has not moved for
+850 s, because it has not.
+
+⚠️ `RELEASE_S` IS `BATT_OBLIGED_S`, 17.0 s, AND IT IS THE FLOOR OF ITS BAND
+RATHER THAN A PREFERENCE - the mirror of `MOVE_W` taking the ceiling of its
+own. The question the bound answers is *has the register had its chance to
+answer the command that is now standing?*, and that is exactly the 17.0 s
+already derived above: 6.0 s of plant, one 10 s publish, one 1 s read. Below it
+the release happens before the cheaper exit - the register moving by itself -
+could have occurred. Which half is safe is the opposite of SAFETY-13's, and for
+the reason that card states in its §4.2 table: being wrong LONG here is the
+failure being fixed (a site parked while it exports), and being wrong SHORT
+costs one re-grading window, which is bounded below.
+
+WHAT A RELEASE COSTS, MEASURED AND NOT ABSORBED - AND IT IS NOT SMALL. For the
+duration of the new window the consumers get the held number again, which is
+the exposure this module was written to close. Driven at the live install's
+shape against a register frozen for good (`test_freshness.py` part 10c), over
+1200 s:
+
+    shipped     parked 1166 s, the held number reaches a consumer  35 s   2.9 %
+    SAFETY-57   parked  571 s, the held number reaches a consumer 630 s  52.5 %
+
+⚠️ **52 % IS THE PRICE OF THE EXIT AND IT IS PAID EVERY CYCLE**, not an
+occasional slip. The period is the whole of `stale_input_s` (15 s) + `RELEASE_S`
+(17 s) parked, then one `BATT_UNCHANGED_S` (35 s) window of re-grading. It is
+bounded by construction, and that bound is the one thing that makes it payable:
+
+    the new window is AT MOST BATT_UNCHANGED_S = 35 s, and 35 < 75 < 85 - the
+    circulation hold and the per-unit sign hold. NEITHER CONSUMER CAN REACH A
+    VERDICT INSIDE ONE WINDOW, and a re-trip returns them a None, which CLEARS
+    both windows rather than accumulating into them.
+
+That inequality is the same one part 6 already grades, and it is why the window
+is `BATT_UNCHANGED_S` rather than a number chosen to make the table above look
+better. Neither detector can be made to say anything by a held number under
+this scheme - which is exactly the state the shipped code leaves them in as
+well, since a permanent None clears both windows for ever. **So nothing that
+SAFETY-37 detects is given back.** What the held number does reach for those
+35 s is `site_batt_w`, the anti-windup input of `control.compute()`, which
+responds to a large unexplained divergence by FREEZING the output - the
+conservative direction, and SAFETY-13's business. And the command itself is
+derived from the P1 meter, never from `batt`, so a site regulating through a
+re-grading window is regulating on the signal it always regulates on.
+
+**A register frozen under a command that never travels 250 W is still not
+detected at all** (survivor 2, unchanged), and a dead publisher whose value
+alternates is still invisible (survivor 3).
+
+⚠️ AND THE NARROWING THIS DOES NOT TAKE, named so the next card can. The live
+episode's register refused a DISCHARGE into an 11 % pack and then followed a
+CHARGE immediately; a refusal in one direction is not evidence about the other,
+and a gate that knew the pack's floor could re-grade on the first command that
+crosses it instead of on a timer. That needs SoC, which this module deliberately
+does not take (see the `soc` row), and the pack floor, which is SAFETY-32's
+number. It would shrink the 52 % above; it is not needed to give the state an
+exit, and mixing it in here would make the exit depend on a second measurement
+being right.
+
+⚠️ WHAT THIS DOES NOT DO, because the temptation is to call it a fix for the
+whole episode: it does not tell a BMS refusal apart from a dead register. The
+site above was parked for 790 s by a register that was working perfectly, and
+after this change it is parked for `stale_input_s + RELEASE_S` instead - about
+32 s on the shipped default - and then regrades. Telling the two apart needs
+the pack's own floor, which is SAFETY-32's number and not this module's input;
+the wording the operator reads about it is SAFETY-56's.
 """
 
 import time
@@ -211,6 +329,19 @@ BATT_UNCHANGED_S = 35.0
 # and goes red if the two drift.
 MOVE_W = 250.0
 
+# SAFETY-57. How long the obligation must have been ABSENT before a standing
+# verdict is withdrawn and the register re-graded. See the module docstring's
+# last section for the live episode this exists for and for which half of the
+# band is the safe one.
+#
+# ⚠️ IT IS `BATT_OBLIGED_S` AND NOT A NEW NUMBER, and that identity is the
+# derivation rather than a convenience. The question is "has the register had
+# its chance to answer the command standing NOW?", which is the same physical
+# quantity the floor of `BATT_UNCHANGED_S`'s band is: 6.0 s of plant, one 10 s
+# ESPHome publish, one 1 s add-on read. Releasing sooner would throw away the
+# cheaper exit - the register moving by itself - before it could have happened.
+RELEASE_S = BATT_OBLIGED_S   # 17.0
+
 
 @dataclass(frozen=True)
 class Bound:
@@ -219,6 +350,7 @@ class Bound:
     signal: str
     unchanged_s: float
     move_w: float
+    release_s: float
     wired: bool
     derivation: str
 
@@ -233,13 +365,19 @@ BOUNDS = {
         signal="batt (0x0518, AC power, S16, 1 W, 10 s publish)",
         unchanged_s=BATT_UNCHANGED_S,
         move_w=MOVE_W,
+        release_s=RELEASE_S,
         wired=True,
         derivation="settle 6.0 + publish 10.0 + read 1.0 = 17.0 s floor; "
-                   "circulation_hold_s 75 s ceiling; band [34.0, 37.5]"),
+                   "circulation_hold_s 75 s ceiling; band [34.0, 37.5]. "
+                   "SAFETY-57: the verdict is withdrawn after 17.0 s of the "
+                   "standing command below 250 W, because at 0 W the register "
+                   "is obliged to nothing and the verdict cannot be tested "
+                   "again from inside the state it creates"),
     "soc": Bound(
         signal="soc (0x050E, pack SoC, U16, 1 %, 10 s publish)",
         unchanged_s=float("inf"),
         move_w=float("inf"),
+        release_s=float("inf"),
         wired=False,
         derivation="TEL-08. Command travel is the WRONG obligation term for "
                    "SoC - a rested pack holds a percent for hours under a 0 W "
@@ -263,10 +401,33 @@ class Freshness:
     Declaring the reading stale makes `Controller.inputs_ok` False, which
     commands 0 W (§11.1 rule 1), which drops the standing command below
     `MOVE_W`, which un-arms the conjunction, which would return the held number
-    to the consumers - and round again every read. So the ONLY thing that clears
-    the latch is an arrival carrying a DIFFERENT number, which is exactly the
-    evidence the verdict was about. A register that is working clears it on its
-    next 10 s publish; a register that is not, does not.
+    to the consumers - and round again every read. So an arrival carrying a
+    DIFFERENT number clears the latch, which is exactly the evidence the verdict
+    was about. A register that is working clears it on its next 10 s publish; a
+    register that is not, does not.
+
+    ⚠️ AND IT IS NOT THE ONLY THING THAT CLEARS IT ANY MORE (SAFETY-57), BECAUSE
+    THAT MADE THE STATE INESCAPABLE FROM INSIDE. The command the verdict itself
+    produces is 0 W, and at 0 W the register is obliged to be nowhere - so
+    "report a different value" is evidence a parked site cannot ask for. The
+    live site sat at 0 W for 790 s on 2026-09-21 with a register that was
+    working correctly, and was freed by a human. `_release()` below withdraws a
+    verdict whose obligation has been gone for `bound.release_s`, and opens a
+    new grading window at that instant. The 1 Hz oscillation the latch exists to
+    prevent is still prevented: the new window is `bound.unchanged_s` wide, so
+    no re-trip can land sooner than 35 s after a release, rather than on the
+    next read. ⚠️ MEASURED FROM THE RELEASE, NOT FROM THE COMMAND RESUMING - if
+    the site rests for longer than the window before it asks for anything, the
+    window is already old and the re-trip lands on the first read at which the
+    command travels 250 W again. That is survivor 5's shape, it predates this
+    card, and its cost is one `stale_input_s` hold.
+
+    ⚠️ TWO CLOCKS, AND THE DISTINCTION IS THE WHOLE OF SAFETY-57'S HONESTY.
+    `changed_mono` / `held` are facts about the REGISTER: when it last carried a
+    different number. `graded_from` / `standing_at_grade` are the window the
+    VERDICT is computed over, which a release re-opens. They are the same thing
+    until the first release and diverge afterwards, and `unchanged_s()` - the
+    number an operator reads - is always the register's.
     """
 
     def __init__(self, bound: Bound):
@@ -281,10 +442,20 @@ class Freshness:
         # ability to fetch it.
         self.held = None
         self.changed_mono = None
-        # The standing command at that same instant. The conjunction compares
-        # against THIS, not against the previous cycle's command: what matters
-        # is whether the register has followed anything since it last moved.
-        self.standing_at_change = None
+        # SAFETY-57. The window the VERDICT is graded over, as opposed to the
+        # register's own history above, and the standing command at the instant
+        # it opened. The conjunction compares against THIS, not against the
+        # previous cycle's command: what matters is whether the register has
+        # followed anything since the current question was put to it. A register
+        # that moves opens a window, so until the first release these two are
+        # the change-stamps; `_release()` is where they diverge.
+        self.graded_from = None
+        self.standing_at_grade = None
+        # The instant the standing command last FELL below `move_w`, or None
+        # while an obligation is standing. The release timer runs off this.
+        self.rested_since = None
+        self.released_at = None
+        self.releases = 0
         self.stale = False
         self.reason = ""
         self.arrivals = 0
@@ -311,20 +482,67 @@ class Freshness:
         if self.changed_mono is None or value != self.held:
             self.held = value
             self.changed_mono = float(now_mono)
-            self.standing_at_change = (None if standing_w is None
-                                       else float(standing_w))
-            # Movement is the ONLY thing that clears the latch. See the class
-            # docstring on the 1 Hz oscillation this prevents.
+            self._open_window(standing_w, now_mono)
+            # Movement clears the latch, because it is exactly the evidence the
+            # verdict was about. See the class docstring on the 1 Hz oscillation
+            # the latch prevents, and `_release()` for the other way out.
             self.stale = False
             self.reason = ""
         self.last = value
+        # ⚠️ THE ORDER OF THESE TWO IS NOT OBSERVABLE, AND THIS COMMENT SAYS SO
+        # BECAUSE THE FIRST VERSION OF IT CLAIMED THE OPPOSITE. Swapping them is
+        # a ZERO-BYTE edit and it SURVIVED the battery; the reason is structural
+        # rather than a missing fixture, so no fixture could have closed it:
+        # `_grade()` acts only when `|standing| >= move_w` and `_release()` only
+        # when `|standing| < move_w`, so at most one of them can do anything on
+        # any given read, whichever runs first. Release is written first because
+        # it reads in the order the state machine moves - withdraw, then
+        # re-grade - not because the code depends on it.
+        self._release(standing_w, now_mono)
         self._grade(standing_w, now_mono)
 
+    def _open_window(self, standing_w, now_mono) -> None:
+        """Start grading the register again, from this instant (SAFETY-57).
+
+        Called when the register moves - the window and the register's history
+        coincide there - and when a verdict is withdrawn, where they do not.
+        """
+        self.graded_from = float(now_mono)
+        self.standing_at_grade = (None if standing_w is None
+                                  else float(standing_w))
+
+    def _release(self, standing_w, now_mono) -> None:
+        """SAFETY-57. Withdraw a verdict whose obligation is no longer standing.
+
+        ⚠️ THE TIMER RUNS ON THE COMMAND, NOT ON THE VERDICT. `rested_since` is
+        maintained on every arrival, latched or not, so the elapsed rest is the
+        real one and not "time since we last looked". An obligation reappearing
+        resets it to None, which is the whole point: a site that goes back to
+        asking the register for 250 W of movement has put the question back, and
+        the verdict stands until the question is withdrawn again.
+        """
+        obliged = (standing_w is not None
+                   and abs(float(standing_w)) >= self.bound.move_w)
+        if obliged:
+            self.rested_since = None
+            return
+        if self.rested_since is None:
+            self.rested_since = float(now_mono)
+        if not self.stale:
+            return
+        if float(now_mono) - self.rested_since < self.bound.release_s:
+            return
+        self.released_at = float(now_mono)
+        self.releases += 1
+        self.stale = False
+        self.reason = ""
+        self._open_window(standing_w, now_mono)
+
     def _grade(self, standing_w, now_mono) -> None:
         """The conjunction. Sets the latch; never clears it."""
-        if self.stale or self.changed_mono is None:
+        if self.stale or self.graded_from is None:
             return
-        held_s = self.unchanged_s(now_mono)
+        held_s = self.graded_s(now_mono)
         if held_s < self.bound.unchanged_s:
             return
         # ⚠️ BOTH None GUARDS ARE FOR A CALLER THAT DOES NOT KNOW ITS OWN
@@ -333,30 +551,93 @@ class Freshness:
         # consumer today. They are here for TEL-08, whose obligation term is an
         # energy integral that has nothing to say until it has a window - and
         # "nothing to say" must withhold the verdict, not manufacture one.
-        if standing_w is None or self.standing_at_change is None:
+        if standing_w is None or self.standing_at_grade is None:
             return
         standing_w = float(standing_w)
         if abs(standing_w) < self.bound.move_w:
             return
-        moved_w = abs(standing_w - self.standing_at_change)
+        moved_w = abs(standing_w - self.standing_at_grade)
         if moved_w < self.bound.move_w:
             return
         self.stale = True
+        # ⚠️ THE SENTENCE SAYS "unchanged", SO IT GETS THE REGISTER'S OWN
+        # NUMBER, NOT THE WINDOW'S. They are the same until the first release
+        # and different afterwards, and an operator comparing this line against
+        # a history graph is reading the register.
+        shown_s = self.unchanged_s(now_mono)
+        # ⚠️ SAFETY-56. THE OBSERVATION IS A FACT, THE DIAGNOSIS WAS NOT, AND
+        # THE SENTENCE NOW STOPS WHERE THE EVIDENCE DOES. The conjunction above
+        # is satisfied by TWO disjoint worlds, and nothing this object is handed
+        # separates them:
+        #   (1) the register has stopped reporting reality - what the gate was
+        #       built for - or
+        #   (2) reality is not moving, because the SOURCE cannot comply with
+        #       the command. A pack the BMS is refusing at its floor holds
+        #       still under any setpoint, and a register reporting that
+        #       truthfully publishes the same unchanged number a dead one does.
+        # The live 2026-09-21 episode was (2) - the pack read 11 % for the
+        # whole 850 s hold, the commands were discharge-only, and the register
+        # answered the first CHARGE command within one obligation window
+        # (test_freshness.py 11a measures all three off the committed capture)
+        # - and this sentence asserted (1), which sent the operator to look at
+        # healthy hardware.
+        # Naming both is what the module can honestly say. Naming WHICH would
+        # need SoC and the pack floor - deliberately not this module's inputs
+        # (see the `soc` row in BOUNDS and the docstring's last section), and
+        # TEL-08's and SAFETY-32's numbers rather than this sentence's.
+        #
+        # ⚠️ AND IT IS NOT SHARED WITH `main.py`'s NOT READY ROW, WHICH SAYS
+        # THE SAME AMBIGUITY IN DIFFERENT WORDS ON PURPOSE. This sentence is a
+        # LOG LINE about a behaviour, quoted verbatim by `note()` onto the
+        # status page and by `_read_unit()` into the action log; that one is a
+        # BANNER about a named ENTITY, and the two answer different questions
+        # ("what did the register do" against "can I trust this entity"). One
+        # helper serving both would have to drop whichever half the other does
+        # not need, and the half it dropped would be the operator's next step.
+        # UX-10: two plain sentences (test_messages.py part 6). SAFETY-56's
+        # two explanations stay, in this order, and so does the admission
+        # that this check cannot tell them apart. The reading is treated as
+        # missing either way, which the log line around this says. The
+        # limits (`self.bound`) are on main.py's DEBUG line beside it, so the
+        # logged line stays within 3 sentences.
+        # ⚠️ SAFETY-57, AND THE THREE DURATIONS ARE THREE DIFFERENT FACTS, each
+        # in its own slot: the register's unchanged time, the WINDOW this
+        # verdict actually rests on after a release (`regraded`), and how many
+        # times this unit has been round the loop. Without the second one the
+        # sentence reads as though 92 s of unchanged register were what was
+        # compared against the 35 s limit, and it was not.
+        regraded = (f", checked {self.releases + 1} times over a {held_s:.0f} s "
+                    f"window since the last stop was withdrawn"
+                    if self.releases else "")
         self.reason = (
-            f"STALE_READING: {self.held:+.0f} unchanged for {held_s:.0f} s "
-            f"while the standing command moved {moved_w:.0f} W to "
-            f"{standing_w:+.0f} W - the reading is not following, so it is "
-            f"reported as MISSING rather than as a measurement (limits: "
-            f"unchanged over {self.bound.unchanged_s:.0f} s, command over "
-            f"{self.bound.move_w:.0f} W and moved by over "
-            f"{self.bound.move_w:.0f} W)")
+            f"STALE_READING: {self.held:+.0f} W unchanged for {shown_s:.0f} s "
+            f"while the command moved {moved_w:.0f} W to {standing_w:+.0f} W"
+            f"{regraded}. The reading may have stopped, or the battery may be "
+            f"unable to follow the command, and this check cannot tell which")
 
     def unchanged_s(self, now_mono) -> float | None:
-        """Seconds since an arrival carried a different number. Status page."""
+        """Seconds since an arrival carried a different number. Status page.
+
+        ⚠️ THE REGISTER'S CLOCK, NEVER THE VERDICT'S (SAFETY-57). A release
+        re-opens the grading window; it does not make the register younger, and
+        an operator reading "unchanged for 12 s" off a register that has held
+        one value for 850 s would be reading this module's bookkeeping back as a
+        measurement. `graded_s()` is the other one and is named differently for
+        that reason.
+        """
         if self.changed_mono is None:
             return None
         return max(0.0, float(now_mono) - self.changed_mono)
 
+    def graded_s(self, now_mono) -> float | None:
+        """Seconds the CURRENT verdict window has been open (SAFETY-57).
+
+        Equal to `unchanged_s()` until the first release, and shorter after one.
+        """
+        if self.graded_from is None:
+            return None
+        return max(0.0, float(now_mono) - self.graded_from)
+
     def reading(self):
         """What the consumers get: the value, or None when it cannot be trusted.
 
@@ -366,6 +647,13 @@ class Freshness:
         rather than accumulating it, and `circulation.circulating_w` returns None
         for a roster with a missing term, which clears the circulation window
         too. This module is the thing that was missing between them.
+
+        ⚠️ AND IT CAN GO BACK TO BEING A NUMBER WITHOUT THE REGISTER MOVING
+        (SAFETY-57). That is the exit, and it is bounded rather than free: the
+        window a release opens is `bound.unchanged_s` = 35 s, shorter than both
+        consumer holds (75 s and 85 s), so neither can reach a verdict inside
+        one - and a re-trip hands them a None, which CLEARS their windows. See
+        the module docstring's last section.
         """
         return None if self.stale else self.last
 
@@ -373,6 +661,26 @@ class Freshness:
         """One line for the status page. Empty when there is nothing to say."""
         return f"{unit_name}: {self.reason}" if self.stale else ""
 
+    def release_note(self, unit_name: str) -> str:
+        """SAFETY-57's release, for the log. Empty when nothing was withdrawn.
+
+        ⚠️ IT NAMES WHAT IS AND IS NOT BEING CLAIMED, because a line reading
+        "recovered" would be a lie: nothing has been learned about the register.
+        The verdict was withdrawn because it can no longer be tested, and the
+        next 35 s are the test.
+        """
+        if self.released_at is None:
+            return ""
+        return (f"{unit_name}: STALE_WITHDRAWN after the standing command sat "
+                f"below {self.bound.move_w:.0f} W for "
+                f"{self.bound.release_s:.0f} s. NOTHING HAS BEEN LEARNED ABOUT "
+                f"THE REGISTER - it is still holding {self.held:+.0f} - but a "
+                f"verdict about a command that is no longer standing cannot be "
+                f"tested, and the 0 W this one produces is what stopped it "
+                f"being tested. The register is now re-graded over a fresh "
+                f"{self.bound.unchanged_s:.0f} s window; if it still does not "
+                f"follow, this returns")
+
 
 def monotonic() -> float:
     """The clock this module's callers use, in one place so tests can find it.

goodwe_controller/app/haentities.py

@@ -0,0 +1,115 @@
+"""UX-13: Home Assistant's entities, for the settings page's entity picker.
+
+A read of `GET /api/states` through the add-on's own session (hass.states()),
+cached for 30 s and trimmed to what a picker shows. Nothing here writes, so
+UX-02 §6 holds. When Home Assistant does not answer, the last good list is
+served with its age, or an empty one that says why: the route never fails.
+"""
+
+import asyncio
+import time
+
+CACHE_S = 30.0
+DOWN_TEXT = "Home Assistant is not answering, so the entity list is empty."
+STALE_TEXT = "Home Assistant is not answering, so this list may be old."
+_POWER_UNITS = ("mW", "W", "kW", "MW", "GW", "TW")
+_TO_W = {"mW": 0.001, "W": 1.0, "kW": 1000.0, "MW": 1e6}
+_ENERGY_UNITS = ("Wh", "kWh", "MWh", "GWh")
+
+
+def row(state: dict) -> dict | None:
+    """One state object -> {entity_id, name, state, unit, device_class}."""
+    if not isinstance(state, dict) or not isinstance(state.get("entity_id"), str):
+        return None
+    attrs = state.get("attributes") if isinstance(state.get("attributes"), dict) else {}
+    return {"entity_id": state["entity_id"],
+            "name": str(attrs.get("friendly_name") or state["entity_id"]),
+            "state": state.get("state"),
+            "unit": attrs.get("unit_of_measurement"),
+            "device_class": attrs.get("device_class")}
+
+
+def watts(r: dict | None):
+    """A power entity's reading in W, or None when it is not a number in a
+    power unit (the setup wizard's kettle test)."""
+    if not r or r.get("unit") not in _TO_W:
+        return None
+    try:
+        value = float(r.get("state"))
+    except (TypeError, ValueError):
+        return None
+    return value * _TO_W[r["unit"]] if value == value else None
+
+
+def matches(r: dict, kind: str) -> bool:
+    """Is `r` what a picker of this kind offers first? `kind` is one of
+    uilayout.ENTITY_KINDS; "" or "any" offers everything."""
+    unit, cls = r.get("unit"), r.get("device_class")
+    if kind in ("power", "power_w"):
+        return cls == "power" or unit in _POWER_UNITS
+    if kind == "energy":
+        return cls == "energy" or unit in _ENERGY_UNITS
+    if kind == "pct":
+        return unit == "%"
+    if kind == "number":
+        return r["entity_id"].startswith(("number.", "input_number."))
+    return True
+
+
+class EntityCache:
+    """The last entity list read from Home Assistant, at most CACHE_S old."""
+
+    def __init__(self, hass, clock=time.monotonic):
+        self.hass = hass
+        self.clock = clock
+        self.rows: dict | None = None
+        self.read_at: float | None = None
+        self.tried_at: float | None = None
+        self._lock = asyncio.Lock()
+
+    async def get(self, max_age: float = CACHE_S
+                  ) -> tuple[dict | None, float | None]:
+        """(rows by entity id, age in s), or (None, None) if never read.
+        `max_age` is how old a try may be before HA is asked again: the setup
+        wizard's last step asks for a list at most a few seconds old."""
+        async with self._lock:      # one HA read however many pickers ask
+            now = self.clock()
+            # A failed read also waits CACHE_S, so polls while HA is down do
+            # not queue one 10 s read each behind this lock.
+            if self.tried_at is None or now - self.tried_at >= max_age:
+                self.tried_at = now
+                states = await self.hass.states()
+                if states is not None:
+                    rows = (row(s) for s in states)
+                    self.rows = {r["entity_id"]: r for r in rows if r}
+                    self.read_at = now
+            if self.read_at is None:
+                return None, None
+            return self.rows, now - self.read_at
+
+    async def reading(self, entity_id: str) -> dict:
+        """One entity read now, not from the list: the kettle test compares
+        two readings seconds apart, which a 30 s list cannot. A read only."""
+        r = row(await self.hass.state(entity_id)) if entity_id else None
+        return {"entity_id": entity_id, "found": r is not None,
+                "state": r and r["state"], "unit": r and r["unit"],
+                "watts": watts(r)}
+
+    def peek(self) -> dict | None:
+        """The cached rows if they are fresh, without asking Home Assistant."""
+        if self.read_at is None or self.clock() - self.read_at >= CACHE_S:
+            return None
+        return self.rows
+
+    async def payload(self, kind: str = "") -> dict:
+        """The route's JSON: matching entities first, then the rest."""
+        rows, age = await self.get()
+        if rows is None:
+            return {"available": False, "text": DOWN_TEXT, "entities": []}
+        ordered = sorted(rows.values(), key=lambda r: r["entity_id"])
+        first = [dict(r, match=True) for r in ordered if matches(r, kind)]
+        rest = [dict(r, match=False) for r in ordered if not matches(r, kind)]
+        out = {"available": True, "age_s": round(age, 1), "entities": first + rest}
+        if age >= CACHE_S:
+            out["text"] = STALE_TEXT
+        return out

goodwe_controller/app/hass.py

@@ -16,6 +16,39 @@ _LOG = logging.getLogger("goodwe.hass")
 CORE_API = "http://supervisor/core/api"
 SUPERVISOR_API = "http://supervisor"
 BAD_STATES = ("unknown", "unavailable", "none", "")
+# What the Supervisor's proxy answers while Home Assistant restarts.
+UNAVAILABLE = (502, 503, 504)
+STATES_TIMEOUT_S = 10       # UX-13's entity list, like every other read here
+
+
+class Outage:
+    """UX-10: Home Assistant not answering, said in one plain line per outage.
+
+    A restart takes the REST API and the meter websocket down together, and
+    each used to log the library's own text for every entity and service
+    ("502, message='Bad Gateway', url=URL(...)", "Received message 8:1000 is
+    not str"). Now the first channel to fail says it once at WARNING, the raw
+    text goes to DEBUG, and the last channel to recover says so at INFO.
+    """
+
+    def __init__(self):
+        self.down_on = set()
+
+    def down(self, channel: str, what: str, detail) -> None:
+        if not self.down_on:
+            _LOG.warning("Home Assistant is not answering (%s), perhaps it is "
+                         "restarting. The add-on keeps trying.", what)
+        self.down_on.add(channel)
+        _LOG.debug("Home Assistant not answering on %s: %s", channel, detail)
+
+    def up(self, channel: str) -> None:
+        if channel in self.down_on:
+            self.down_on.discard(channel)
+            if not self.down_on:
+                _LOG.info("Home Assistant answers again.")
+
+
+OUTAGE = Outage()
 
 
 class HomeAssistant:
@@ -58,13 +91,61 @@ class HomeAssistant:
             async with self.session.get(
                 f"{CORE_API}/states/{entity_id}", headers=self._headers, timeout=10
             ) as resp:
+                if resp.status in UNAVAILABLE:
+                    OUTAGE.down("api", f"error {resp.status}",
+                                f"read {entity_id}: {resp.status}")
+                    return None
+                OUTAGE.up("api")
                 if resp.status == 404:
                     return None
                 resp.raise_for_status()
-                return await resp.json()
-        except (aiohttp.ClientError, TimeoutError) as err:
+                obj = await resp.json()
+        except aiohttp.ClientConnectionError as err:
+            OUTAGE.down("api", "no connection", f"read {entity_id}: {err}")
+            return None
+        # SAFETY-61: an undecodable body is an absence like any other failed
+        # read, never an exception into the control loop.
+        except (aiohttp.ClientError, TimeoutError, ValueError) as err:
             self._moan(f"read:{entity_id}", "read %s failed: %s", entity_id, err)
             return None
+        if not isinstance(obj, dict):
+            self._moan(f"shape:{entity_id}", "read %s: not a state object: %.80r",
+                       entity_id, obj)
+            return None
+        return obj
+
+    async def states(self) -> list | None:
+        """Every entity's state object (`GET /api/states`), or None when Home
+        Assistant does not answer. A read only (UX-13 entity picker)."""
+        try:
+            async with self.session.get(
+                f"{CORE_API}/states", headers=self._headers,
+                timeout=STATES_TIMEOUT_S
+            ) as resp:
+                if resp.status in UNAVAILABLE:
+                    OUTAGE.down("api", f"error {resp.status}",
+                                f"read all states: {resp.status}")
+                    return None
+                OUTAGE.up("api")
+                resp.raise_for_status()
+                obj = await resp.json()
+        except aiohttp.ClientConnectionError as err:
+            OUTAGE.down("api", "no connection", f"read all states: {err}")
+            return None
+        # A timeout's own text is empty, so the line names the wait instead
+        # (UX-13 P1 test, c).
+        except TimeoutError:
+            self._moan("read:*", "Reading the entity list failed: no answer "
+                       "within %s seconds.", STATES_TIMEOUT_S)
+            return None
+        except (aiohttp.ClientError, ValueError) as err:
+            self._moan("read:*", "Reading the entity list failed: %s",
+                       str(err) or type(err).__name__)
+            return None
+        if not isinstance(obj, list):
+            self._moan("shape:*", "The entity list is not a list: %.80r", obj)
+            return None
+        return obj
 
     async def number(self, entity_id: str, invert: bool = False) -> float | None:
         """Numeric state, or None. Never substitutes a default."""
@@ -106,18 +187,39 @@ class HomeAssistant:
                 f"{CORE_API}/services/{domain}/{service}",
                 headers=self._headers, json=data, timeout=10,
             ) as resp:
+                if resp.status in UNAVAILABLE:
+                    OUTAGE.down("api", f"error {resp.status}",
+                                f"service {domain}.{service}: {resp.status}")
+                    return False
+                OUTAGE.up("api")
                 if resp.status >= 400:
                     body = await resp.text()
                     # 400 here usually means out-of-range for the entity - the
                     # value is rejected outright, not clamped. Always log it:
                     # silently dropped commands are how a controller ends up
                     # believing something the hardware never did.
+                    # UX-10: plain words. While Home Assistant loads its
+                    # entities it answers 400 with only "400: Bad Request",
+                    # which says nothing, so only a body with more is quoted.
+                    said = body.strip()[:200]
+                    if said.lower() in (f"{resp.status}: {resp.reason}".lower(),
+                                        ""):
+                        said = "no details"
+                    entity = (data.get("entity_id", "no entity")
+                              if isinstance(data, dict) else "no entity")
                     self._moan(f"svc:{domain}.{service}",
-                               "service %s.%s rejected (%s): %s",
-                               domain, service, resp.status, body[:200])
+                               "Home Assistant refused %s.%s for %s (error %s, "
+                               "%s). The entity may still be loading, or the "
+                               "value is out of range.", domain, service,
+                               entity, resp.status, said)
                     return False
                 return True
-        except (aiohttp.ClientError, TimeoutError) as err:
+        except aiohttp.ClientConnectionError as err:
+            OUTAGE.down("api", "no connection",
+                        f"service {domain}.{service}: {err}")
+            return False
+        # ValueError: an undecodable error body (SAFETY-61) is a failed write.
+        except (aiohttp.ClientError, TimeoutError, ValueError) as err:
             self._moan(f"svcerr:{domain}.{service}", "service %s.%s failed: %s",
                        domain, service, err)
             return False

goodwe_controller/app/inverter.py

@@ -123,6 +123,7 @@ from datetime import datetime
 
 from .clamp import ClampResult
 from .delivery import DeliveryConfig, DeliveryWatchdog
+from . import messages
 # SAFETY-37. The freshness policy, and the ONE place its bounds are written.
 # freshness.py imports nothing from this package, so the direction is one-way.
 from .freshness import BOUNDS, Freshness
@@ -316,6 +317,18 @@ class Inverter:
             tripped=bool(data.get(self.key("delivery_tripped"), False)),
             reason=str(data.get(self.key("delivery_reason"), "") or ""))
 
+        # SAFETY-73. The direction this unit's battery refuses (+1 give, -1
+        # take, 0 none), when that refusal or its last probe started, the
+        # current probe's start, and the cycles of evidence so far and when
+        # they began. Memory only, like SAFETY-52's: stop and start end it.
+        # Used at N>1 only.
+        self.refused = 0
+        self.refused_at = None
+        self.probe_from = None
+        self.ref_count = 0
+        self.ref_since = None
+        self.ref_sign = 0
+
     # -- store ---------------------------------------------------------------
     def key(self, name: str) -> str:
         """This unit's namespaced Store key for `name`. See store.unit_key()."""
@@ -407,21 +420,31 @@ class Inverter:
         stop the site (`inputs_ok`). Folding one into the other is how a
         measurement fault ends up handing a sibling extra power.
         """
-        return self.batt_fresh.note(self.name)
+        return (messages.row_battery_stuck(self.name) if self.batt_fresh.stale
+                else "")
+
+    def refusal_note(self) -> str:
+        """SAFETY-73's status row while this unit's battery refuses."""
+        if not self.refused:
+            return ""
+        return messages.row_battery_refuses(self.name, self.refused,
+                                            self.probe_from is not None)
 
     def link_note(self, now: datetime) -> str:
-        """One line for the status page. Empty when there is nothing to say."""
+        """One line for the status page. Empty when there is nothing to say.
+
+        The words are `app/messages.py`'s (UX-09). main.py colours the row red
+        exactly when `is_live()` is False.
+        """
         if not self.has_writer():
-            return (f"{self.name}: NO SETPOINT ENTITY - this controller cannot "
-                    f"command it, and the site refuses rather than running at "
-                    f"part strength")
-        live, why = self.is_live(now)
+            return messages.row_no_setpoint(self.name)
+        live, _why = self.is_live(now)
+        held = (0.0 if self.rejected_since is None
+                else (now - self.rejected_since).total_seconds())
         if not live:
-            return f"{self.name}: NOT COMMANDABLE - {why}"
+            return messages.row_not_controllable(self.name, held, LINK_STALE_S)
         if self.rejected_since is not None:
-            held = (now - self.rejected_since).total_seconds()
-            return (f"{self.name}: writes rejected for {held:.0f} s - still "
-                    f"commandable until {LINK_STALE_S:.0f} s")
+            return messages.row_commands_refused(self.name, held, LINK_STALE_S)
         return ""
 
     def __repr__(self) -> str:

goodwe_controller/app/maintenance.py

@@ -351,7 +351,7 @@ class Maintenance:
         the action log rather than watching nothing happen.
         """
         if blocked_by:
-            msg = (f"maintenance: forced start REFUSED on {self.name} - "
+            msg = (f"maintenance: {self.name} cannot start now, because "
                    f"{blocked_by}")
             _LOG.warning("%s", msg)
             return [msg]
@@ -378,10 +378,9 @@ class Maintenance:
         """
         if self._deferred != why:
             self._deferred = why
-            msg = (f"maintenance: {self.name} is due and is WAITING its turn - "
-                   f"{why}. It is idle under the control loop and will "
-                   f"recalibrate at the next start hour once the slot is free; "
-                   f"this is not a stalled phase.")
+            msg = (f"maintenance: {self.name} is due and waits its turn, "
+                   f"because {why}. It starts at the next start hour once the "
+                   f"other battery is done. This is not a stalled phase.")
             _LOG.info("%s", msg)
             events.append(msg)
         return events

goodwe_controller/app/mqtt.py

@@ -85,8 +85,114 @@ SENSORS = [
     # sensor's VALUE rather than its arrival, so a dead publisher freezes the
     # number and reads permanently fresh. Filed as TEL-06.
     ("p1_age", "p1_sample_age_s", "P1 sample age", "s", "duration", "measurement", None),
+    # --- TEL-10: the loop's integrator, published for the first time ---------
+    #
+    # ⚠️ APPENDED, AND THE POSITION IS THE POINT. `discovery_payloads()` walks
+    # this list in order and `_announce()` publishes what it returns, so a row
+    # inserted ABOVE would move every later entity's place in the announcement.
+    # Nothing existing is renamed, re-typed or re-ordered by these three; they
+    # are three NEW retained topics after the nine that are already there, and
+    # test_mqtt.py part 1 grades exactly that claim.
+    #
+    # ⚠️ AND THEY ARE SITE ROWS, NOT PER-UNIT ONES. There is one integrator -
+    # §6.2's architecture is ONE integrator on the P1 meter whose output is then
+    # SPLIT - so a per-unit copy would invent N of a thing there is one of, the
+    # same argument `grid` and `p1_age` are site rows for.
+    #
+    # `state_class: measurement` on the two numbers is what puts them in the
+    # recorder's statistics, which is the whole point: the reason this card
+    # exists is that the last investigation had no history to read.
+    ("loop_i", "goodwe_loop_integrator", "Loop integrator", "W", "power", "measurement", None),
+    # ⚠️ NOT DERIVABLE FROM THE TWO ROWS EITHER SIDE OF IT, which is why it is
+    # its own row rather than a subtraction a dashboard could do. `setpoint` is
+    # the ARBITER's output after every other strategy has had its say, and it is
+    # also THIS cycle's; the lead is measured against the command `compute()`
+    # was handed, which is the PREVIOUS one. Subtracting the published rows
+    # gives a different number on every cycle the arbiter overrode the loop.
+    ("loop_lead", "goodwe_loop_integrator_lead", "Loop integrator lead", "W", "power", "measurement", None),
+    # ⚠️ NOT `sensor.goodwe_controller_status` AND NOT THE "Why" ROW. Both of
+    # those carry the ARBITER's sentence; this is `compute()`'s own word for
+    # what the control law did with this cycle - `slew-limited` is the value
+    # SAFETY-48 is about and it appears in neither of the other two.
+    ("loop_reason", "goodwe_loop_reason", "Loop reason", None, None, None, "mdi:sigma"),
 ]
 
+# --- TEL-11: rows that exist ONLY when the operator configured a source ------
+#
+# ⚠️ A SECOND LIST RATHER THAN A TENTH ENTRY IN `SENSORS`, AND THE DEFAULT IS
+# WHAT MAKES IT ONE. `SENSORS` is announced by every caller of
+# `discovery_payloads()`; `OPTIONAL_SENSORS` is announced only by a caller that
+# ASKS, so a caller that has not been taught about `pv_entity` - `test_mqtt.py`'s
+# fixtures, `tools/rehearse_roster.py`, anything written next year - announces
+# exactly what it announced before. `p1_age` solves the same problem the other
+# way round, with `omit`, because `p1_age` is announced by DEFAULT and withdrawn
+# when the meter is off; this one does not exist by default and appears when a
+# source for it does. Getting that direction wrong is the hazard `omit`'s own
+# note names: an entity that exists and is never fed is a worse signal than one
+# that does not exist at all, and MOST installs will never set `pv_entity`.
+#
+# ⚠️ `state_class: measurement` IS THE WHOLE POINT OF THE ROW. It is what puts
+# the number into the recorder's long-term statistics, and a week of statistics
+# is what OPT-10 needs to say whether the surplus that left this site was cloud,
+# a charge-power limit, or the optimiser declining to charge.
+OPTIONAL_SENSORS = [
+    ("pv", "goodwe_pv_power", "PV power", "W", "power", "measurement", None),
+]
+
+# ⚠️ HA's OWN "this sensor has no value" PAYLOAD, and the one place this add-on
+# spells it. `homeassistant/components/mqtt/const.py` declares
+# `PAYLOAD_NONE = "None"` and `mqtt/sensor.py` tests it BEFORE the numeric
+# branch - `if payload == PAYLOAD_NONE: self._attr_native_value = None` - so the
+# entity's state becomes `unknown` rather than a number. (Read out of
+# github.com/home-assistant/core `dev` on 2026-09-24; the shipped MQTT-sensor
+# documentation says the same thing in its `state_topic` entry: "a 'None' value
+# will set the sensor to an unknown state".)
+PAYLOAD_NONE = "None"
+
+# The keys whose ABSENCE MUST BE PUBLISHED rather than skipped. ⚠️ THIS IS THE
+# DIFFERENCE BETWEEN "no PV reported" AND "PV reported 0 W" IN A WEEK OF
+# HISTORY, AND WITHOUT IT THE CHANNEL LIES IN THE WORSE DIRECTION. `publish()`
+# below drops a `None` - which is right for `circulation`, where the last figure
+# standing is better than a zero that reads as health - but a DROPPED pv row
+# leaves Home Assistant holding the last number it was told, forever, and the
+# recorder then draws a flat line at that value through an outage. Someone
+# reading it back would conclude the sun was not shining, which is precisely the
+# conclusion this card exists to TEST rather than to manufacture.
+ABSENT_AS_UNKNOWN = frozenset({"pv"})
+
+
+def optional_keys(opts: dict) -> tuple:
+    """Which `OPTIONAL_SENSORS` rows this configuration has a source for.
+
+    ⚠️ ONE ANSWER TO "IS THE PV ROW LIVE", read by the ANNOUNCEMENT (through
+    `MqttPublisher`) and by `Controller.publish()`. `announced_units()` above
+    exists for exactly this reason and says it in full: two spellings of one
+    predicate is how an entity gets announced that nothing feeds, or fed on a
+    topic nothing announced.
+
+    ⚠️ AND SINCE TEL-12 IT IS `pv.entities()` RATHER THAN A SECOND READING OF
+    THE OPTION - `Controller.pv_roster` is the SAME call. TEL-11 got away with
+    two spellings because both were `bool()` of one string; with `pv_entities`
+    beside `pv_entity`, and `pv_entities` REPLACING it, a second spelling is how
+    the row gets announced off one key and summed off the other. ⚠️ THE ROW IS
+    ONE SITE TOTAL AT EVERY ROSTER SIZE: there is deliberately no per-entity
+    topic, because the recorder statistic OPT-10 reads back is the site figure
+    and a per-inverter breakdown is a dashboard question the operator's own PV
+    integration already answers.
+    """
+    # ⚠️ THE IMPORT IS FUNCTION-LOCAL AND THAT IS NOT A STYLE CHOICE. This
+    # module is EXEC'D STANDALONE, outside its package, by `test_mqtt.py`
+    # part 8's mutation harness - which says so in its own comment, and whose
+    # honesty depends on it ("`app/mqtt.py` imports nothing from this package,
+    # which is what makes exec'ing it standalone honest rather than a stub").
+    # A module-scope `from . import pv` turns that whole instrument into an
+    # `ImportError` before it grades anything. `tools/tel11_pv_trace.py`'s
+    # `_load()` is the same decision for the same kind of reason. Measured, not
+    # assumed: move this line to module scope and test_mqtt.py part 8 dies.
+    from . import pv as _pv
+    return ("pv",) if _pv.entities(opts) else ()
+
+
 BASE = "goodwe_ctl"
 AVAILABILITY = f"{BASE}/availability"
 
@@ -269,15 +375,23 @@ def _payload(name, object_id, unique_id, state_topic, device,
     return cfg
 
 
-def discovery_payloads(units=(), omit=()) -> list:
+def discovery_payloads(units=(), omit=(), include=()) -> list:
     """Every `(topic, payload)` this add-on announces, in announcement order.
 
     Split out of `_announce()` so that the acceptance criterion can be graded as
     a DIFF OF THE ANNOUNCED PAYLOADS against `release/1.0`, rather than as a
     reading of the code. `_announce()` publishes exactly this list and nothing
     else, which is itself checked.
+
+    `include` names `OPTIONAL_SENSORS` keys to announce. ⚠️ IT DEFAULTS TO
+    NOTHING AND THE ROWS GO LAST, so no existing row's POSITION moves under any
+    configuration - not the site rows, not the per-unit ones. Order is part of
+    the output here (`_payload()`'s note, and test_mqtt.py part 1 asserts an
+    ordered LIST precisely because a re-order is a zero-byte edit that
+    re-announces every entity on a live install).
     """
     omit = set(omit)
+    include = [k for k in include if k not in omit]
     out = []
     for key, object_id, name, unit, dev_class, state_class, icon in SENSORS:
         if key in omit:
@@ -306,12 +420,19 @@ def discovery_payloads(units=(), omit=()) -> list:
                          unique_id,
                          f"{BASE}/{unit_state_key(slug, key)}",
                          device, unit, dev_class, state_class, icon)))
+    for key, object_id, name, unit, dev_class, state_class, icon in OPTIONAL_SENSORS:
+        if key not in include:
+            continue
+        out.append((
+            f"homeassistant/sensor/{BASE}_{key}/config",
+            _payload(name, object_id, f"{BASE}_{key}", f"{BASE}/{key}",
+                     DEVICE, unit, dev_class, state_class, icon)))
     return out
 
 
 class MqttPublisher:
     def __init__(self, host, port, username=None, password=None, omit=(),
-                 units=()):
+                 units=(), include=()):
         # `omit` drops sensor keys from discovery entirely. ⚠️ Announcing a
         # sensor that nothing will ever publish to is not harmless here:
         # p1_sample_age_s is a watchdog input, and an entity that exists but is
@@ -323,6 +444,10 @@ class MqttPublisher:
         # per-unit is announced, so every caller that has not been taught about
         # the roster keeps publishing what it published before.
         self.units = [str(u) for u in units]
+        # TEL-11. `mqtt.optional_keys(opts)` - the shipped predicate, not a
+        # second reading of the option. Defaults to empty, so a caller that has
+        # not been taught about it announces exactly what it announced before.
+        self.include = [str(k) for k in include]
         self.enabled = mqtt is not None and bool(host)
         self.client = None
         if not self.enabled:
@@ -359,7 +484,8 @@ class MqttPublisher:
         # announcement, so the check that diffs it against `release/1.0` is
         # diffing what actually goes on the wire - and a payload built here
         # instead would be one this add-on publishes and no check has ever seen.
-        for topic, cfg in discovery_payloads(self.units, self.omit):
+        for topic, cfg in discovery_payloads(self.units, self.omit,
+                                             self.include):
             self.client.publish(topic, json.dumps(cfg), retain=True)
         self.client.publish(AVAILABILITY, "online", retain=True)
 
@@ -369,7 +495,16 @@ class MqttPublisher:
         try:
             for key, value in values.items():
                 if value is None:
-                    continue
+                    # ⚠️ TEL-11. A DROPPED ROW IS NOT AN ABSENT ROW. Skipping
+                    # leaves Home Assistant holding the last value it was told,
+                    # which is what `circulation` wants (its note in main.py
+                    # says why) and is exactly wrong for a measurement somebody
+                    # will read back as history: a flat line at the last number
+                    # is indistinguishable from a real one. See
+                    # `ABSENT_AS_UNKNOWN`.
+                    if key not in ABSENT_AS_UNKNOWN:
+                        continue
+                    value = PAYLOAD_NONE
                 self.client.publish(f"{BASE}/{key}", str(value))
         except OSError as err:  # pragma: no cover
             _LOG.debug("MQTT publish failed: %s", err)

goodwe_controller/app/p1.py

@@ -47,6 +47,11 @@ from datetime import datetime, timezone
 
 import aiohttp
 
+from . import messages
+from .hass import OUTAGE
+
+_S = messages.setting   # a refusal names the setting by its label (UX-08)
+
 try:
     import paho.mqtt.client as mqtt
 except ImportError:  # pragma: no cover - container always has it
@@ -180,7 +185,8 @@ def make_sample(source: str, import_w, export_w, *, phases: int,
     # already applied a sign we are about to apply again - reject it rather
     # than silently double-signing the control loop.
     if imp < 0 or exp < 0:
-        raise P1Error(f"unsigned registers cannot be negative (import={imp:g} export={exp:g})")
+        raise P1Error(f"import and export readings cannot be negative "
+                      f"(import={imp:g} export={exp:g})")
 
     per_phase = per_phase_import = None
     if phase_import_w is not None or phase_export_w is not None:
@@ -188,8 +194,8 @@ def make_sample(source: str, import_w, export_w, *, phases: int,
         pe = list(phase_export_w or [0.0] * len(pi))
         if len(pi) != phases or len(pe) != phases:
             raise P1Error(
-                f"phase count mismatch: telegram has {len(pi)} import / {len(pe)} export "
-                f"phases, meter_phases is {phases}")
+                f"the meter sent {len(pi)} import and {len(pe)} export phases, "
+                f"but {_S('meter_phases')} is {phases}")
         vals = [_watts(a, f"L{i + 1} import") - _watts(b, f"L{i + 1} export")
                 for i, (a, b) in enumerate(zip(pi, pe))]
         per_phase = tuple(vals)
@@ -467,7 +473,7 @@ class P1Ingest:
         """
         self.parse_errors += 1
         self.last_error = str(err)
-        _LOG.warning("P1 telegram rejected: %s", err)
+        _LOG.warning("A meter message could not be read: %s", err)
 
     # -- what consumers read -------------------------------------------------
     def age_s(self) -> float | None:
@@ -519,6 +525,16 @@ WS_URL = "ws://supervisor/core/websocket"
 BAD_STATES = ("unknown", "unavailable", "none", "")
 
 
+async def _receive_json(ws):
+    """The next JSON message. A socket Home Assistant closed (a restart) is a
+    ConnectionResetError, not aiohttp's "Received message 8:1000 is not str"."""
+    msg = await ws.receive()
+    if msg.type is not aiohttp.WSMsgType.TEXT:
+        raise ConnectionResetError(
+            f"Home Assistant closed the connection ({msg.type.name})")
+    return json.loads(msg.data)
+
+
 class HaDsmrSource:
     """Subscribes to state_changed for the configured DSMR entities.
 
@@ -569,8 +585,12 @@ class HaDsmrSource:
                 backoff = 1.0
             except asyncio.CancelledError:
                 raise
+            except (aiohttp.ClientError, ConnectionError) as err:
+                # UX-10: Home Assistant restarting, said once (hass.Outage).
+                OUTAGE.down("websocket", "the meter connection closed", err)
             except Exception as err:  # noqa: BLE001 - any transport fault retries
-                _LOG.warning("P1 HA websocket: %s - reconnecting in %.0fs", err, backoff)
+                _LOG.warning("The meter connection to Home Assistant failed "
+                             "(%s), trying again in %.0f s.", err, backoff)
             finally:
                 self.connected = False
             await asyncio.sleep(backoff)
@@ -578,16 +598,17 @@ class HaDsmrSource:
 
     async def _session_once(self) -> None:
         async with self.session.ws_connect(WS_URL, heartbeat=30) as ws:
-            hello = await ws.receive_json()
+            hello = await _receive_json(ws)
             if hello.get("type") == "auth_required":
                 await ws.send_json({"type": "auth", "access_token": self.token})
-                reply = await ws.receive_json()
+                reply = await _receive_json(ws)
                 if reply.get("type") != "auth_ok":
                     raise RuntimeError(f"auth rejected: {reply.get('message', reply)}")
             await ws.send_json({"id": 1, "type": "subscribe_events",
                                 "event_type": "state_changed"})
             await ws.send_json({"id": 2, "type": "get_states"})
             self.connected = True
+            OUTAGE.up("websocket")
             _LOG.info("P1 ingest: subscribed to %s", ", ".join(sorted(self.ids)))
 
             async for msg in ws:
@@ -613,7 +634,7 @@ class HaDsmrSource:
                     new = data.get("new_state") or {}
                     self._absorb(data.get("entity_id"), new.get("state"))
                     self._schedule()
-            raise RuntimeError("websocket closed")
+            raise ConnectionResetError("Home Assistant closed the connection")
 
     def _absorb(self, entity_id: str | None, state) -> None:
         if not entity_id or entity_id not in self.ids:
@@ -1160,37 +1181,37 @@ def validate_meter_options(opts: dict, phases: int, max_age_s: float) -> list[st
         exp = str(opts.get("p1_export_entity", "") or "").strip()
         if not imp or not exp:
             problems.append(
-                f"meter_source {SOURCE_HA} needs both p1_import_entity and "
-                f"p1_export_entity (got {imp or '<blank>'!r} / {exp or '<blank>'!r})")
+                f"{_S('meter_source')} is {SOURCE_HA!r}, so it needs "
+                f"{_S('p1_import_entity')} and {_S('p1_export_entity')}. They "
+                f"are {messages.shown(imp)} and {messages.shown(exp)}.")
     elif source == SOURCE_HA_SIGNED:
         net = str(opts.get("p1_net_entity", "") or "").strip()
         phase_net = [str(e).strip() for e in
                      (opts.get("p1_phase_net_entities") or []) if str(e).strip()]
         if not net:
             problems.append(
-                f"meter_source {SOURCE_HA_SIGNED} needs p1_net_entity "
-                "(sensor.p1_sample_age_s would otherwise be announced with "
-                "nothing feeding it)")
+                f"{_S('meter_source')} is {SOURCE_HA_SIGNED!r}, so it needs "
+                f"{_S('p1_net_entity')}.")
         if phase_net and len(phase_net) != phases:
             problems.append(
-                f"p1_phase_net_entities has {len(phase_net)} entities but "
-                f"meter_phases is {phases} - every telegram would be rejected "
-                "on the phase-count check")
+                f"{_S('p1_phase_net_entities')} has {len(phase_net)} entities, "
+                f"but {_S('meter_phases')} is {phases}. Make them match.")
     elif source == SOURCE_MQTT:
         if not str(opts.get("meter_mqtt_topic", "") or "").strip():
-            problems.append(f"meter_source {SOURCE_MQTT} needs meter_mqtt_topic")
+            problems.append(f"{_S('meter_source')} is {SOURCE_MQTT!r}, so it "
+                            f"needs {_S('meter_mqtt_topic')}.")
     elif source == SOURCE_HOMEWIZARD:
         host, port_s = homewizard_host_port(opts)
         if not host:
             problems.append(
-                f"meter_source {SOURCE_HOMEWIZARD} needs p1_host (the meter's "
-                "own address, e.g. 192.168.2.250)")
+                f"{_S('meter_source')} is {SOURCE_HOMEWIZARD!r}, so it needs "
+                f"{_S('p1_host')}, the meter's address on your network.")
         if port_s:
             try:
                 int(port_s)
             except ValueError:
-                problems.append(f"p1_host {opts.get('p1_host')!r} has an "
-                                "unparseable port")
+                problems.append(f"{_S('p1_host')} is {messages.shown(opts.get('p1_host'))}, and "
+                                "its port is not a number.")
         try:
             # ⚠️ Not `or 5`: that turns an explicit 0 into the default, and a
             # cadence of 0 is a misconfiguration that must be reported, not
@@ -1198,23 +1219,26 @@ def validate_meter_options(opts: dict, phases: int, max_age_s: float) -> list[st
             raw = opts.get("meter_poll_s", 5)
             poll_s = float(5 if raw is None or raw == "" else raw)
         except (TypeError, ValueError):
-            problems.append(f"meter_poll_s {opts.get('meter_poll_s')!r} is not a number")
+            problems.append(f"{_S('meter_poll_s')} is "
+                            f"{messages.shown(opts.get('meter_poll_s'))}, which is not a "
+                            "number.")
         else:
             if poll_s <= 0:
-                problems.append("meter_poll_s must be positive")
+                problems.append(f"{_S('meter_poll_s')} must be above 0.")
             # ⚠️ The age can never be fresher than the poll interval. At or past
             # max_age_s every reading is stale before its successor arrives, so
             # the controller would sit permanently on missing inputs while the
             # meter is perfectly healthy - refuse it rather than ship that.
             elif poll_s >= max_age_s:
                 problems.append(
-                    f"meter_poll_s {poll_s:.1f} is not under meter_max_age_s "
-                    f"{max_age_s:.1f} - every reading would go stale before the "
-                    "next poll")
+                    f"{_S('meter_poll_s')} is {poll_s:.1f}, not below "
+                    f"{_S('meter_max_age_s')} at {max_age_s:.1f}. Poll more "
+                    "often, or every reading goes stale.")
     else:
         problems.append(
-            f"meter_source {source!r} is not one of "
-            + ", ".join((SOURCE_HA, SOURCE_MQTT, SOURCE_HA_SIGNED, SOURCE_HOMEWIZARD)))
+            f"{_S('meter_source')} is {source!r}. Choose one of: off, "
+            + ", ".join((SOURCE_HA, SOURCE_MQTT, SOURCE_HA_SIGNED, SOURCE_HOMEWIZARD))
+            + ".")
     return problems
 
 
@@ -1261,9 +1285,8 @@ def build_source(opts: dict, ingest: P1Ingest, session, broker: dict | None):
         # 0 W cycle, which is fail-safe. The refusal above is for cadences that
         # can NEVER be fresh.
         if poll_s > ingest.max_age_s / 2:
-            _LOG.warning("meter_poll_s %.1f leaves no room under meter_max_age_s "
-                         "%.1f: one missed poll makes the reading stale. The meter "
-                         "updates every ~5 s; 5 s against 30 s is the tested pair.",
+            _LOG.warning("“Time between meter reads” (%.1f s) is too close to "
+                         "“Reading too old after” (%.1f s). Use 5 s and 30 s.",
                          poll_s, ingest.max_age_s)
         return HomeWizardLocalSource(session, ingest, host, port=port, poll_s=poll_s)
     if source == SOURCE_MQTT:

goodwe_controller/app/peakguard.py

@@ -395,33 +395,34 @@ not need re-testing. Nothing here indexes a phase.
 
 from dataclasses import dataclass
 
+from . import messages
 from .arbiter import ACTUATOR_SITE, P_PEAK, Claim
 from .control import peak_at_risk
 from .tariff import QUARTER_S
 
 # Why the projection may not be graded. Reasons, not booleans: the status page
 # and the action log both have to say WHICH, and "blind" alone is unactionable.
-BLIND_NO_BLOCK = "no open quarter - the meter has produced no sample yet"
+BLIND_NO_BLOCK = "no open 15-minute period, the meter has given no reading yet"
 BLIND_COVERAGE = "meter gap"
-BLIND_FROZEN = "SAFETY-18: the meter is answering without changing"
+BLIND_FROZEN = "the meter is answering without changing"
 
 # Where the ceiling came from. Only the second is a relaxation, and only an
 # OBSERVED reading may produce it.
 CEILING_CAP = "peak_cap_w"
-CEILING_MONTH_PEAK = "the month's banked peak"
+CEILING_MONTH_PEAK = "this month's peak"
 
 # SAFETY-24. Why the forced discharge may not be sized. Reasons, not booleans,
 # for BLIND_*'s reason: the status page, the action log and the operator
 # notification all have to say WHICH, and "floor-limited" alone is unactionable.
-FLOOR_SOC_UNREADABLE = ("the battery state of charge was not measured this "
-                        "cycle, and an unreadable SoC is not a full battery")
-# ⚠️ SAFETY-25. "the peak guard's SoC floor", not "the SoC floor", and the
-# possessive is load-bearing: this string is what the status page, the action log
-# and the operator notification all print, and `peak_soc_floor` bounds THIS GUARD
-# ONLY. Widening it to "the SoC floor" would make the one sentence an operator
-# reads at the moment the battery stops shaving into a claim about the pack that
-# the grid-following loop is at that instant disproving.
-FLOOR_AT_SOC_FLOOR = "state of charge is at or below the peak guard's SoC floor"
+FLOOR_SOC_UNREADABLE = ("the battery level was not read this cycle, and "
+                        "unread is not full")
+# ⚠️ SAFETY-25. "the peak reserve", not "the SoC floor", and the name is
+# load-bearing: this string is what the action log and the add-on log print,
+# and `peak_soc_floor` (“Peak reserve”) bounds THIS GUARD ONLY. Widening it to
+# "the SoC floor" would make the one sentence an operator reads at the moment
+# the battery stops shaving into a claim about the pack that the
+# grid-following loop is at that instant disproving.
+FLOOR_AT_SOC_FLOOR = "the battery level is at or below the peak reserve"
 
 SOURCE = "peak"
 
@@ -485,17 +486,29 @@ class PeakDecision:
     reason: str = ""
 
     def explain(self) -> str:
+        """Idle: the status row's plain words (UX-08). Engaged: `reason`, the
+        technical record with every figure, for the log and the action log."""
         if self.floor_limited:
             return self.reason
         if not self.engaged:
             if self.projected_w is None:
-                return f"peak guard idle - {self.reason}"
-            return (f"peak guard idle - quarter projects "
-                    f"{self.projected_w:.0f} W under a {self.ceiling_w:.0f} W "
-                    f"ceiling ({self.ceiling_from})")
+                return messages.row_peak_guard_quiet()
+            return messages.row_peak_guard_idle(
+                self.projected_w, self.ceiling_w,
+                month_peak=self.ceiling_from == CEILING_MONTH_PEAK)
         return self.reason
 
 
+def blind_kind(blind: str) -> str:
+    """Which of the three kinds of blindness, as a key of
+    `messages.BLIND_WORDS`, for the status row."""
+    if blind == BLIND_FROZEN:
+        return "frozen"
+    if blind == BLIND_NO_BLOCK:
+        return "no_block"
+    return "gap"
+
+
 def quarter_ceiling_w(cap_w, reading) -> tuple[float, str]:
     """The average this quarter may not exceed, and where the number came from.
 
@@ -553,8 +566,9 @@ def blindness(projection, max_hold_s, frozen: bool) -> str | None:
         return BLIND_NO_BLOCK
     gap = uncovered_s(projection)
     if max_hold_s is not None and gap > float(max_hold_s):
-        return (f"{BLIND_COVERAGE}: {gap:.0f} s of this quarter uncovered, past "
-                f"the {float(max_hold_s):.0f} s the averager will hold a sample")
+        return (f"{BLIND_COVERAGE}, {gap:.0f} s of this 15-minute period not "
+                f"covered, past the {float(max_hold_s):.0f} s a reading is "
+                f"held")
     return None
 
 
@@ -730,9 +744,9 @@ def decide(projection, *, batt_w, cap_w, reading, achievable_w, soc, soc_floor,
         return PeakDecision(
             engaged=True, floor_w=0.0, ceiling_w=ceiling, ceiling_from=from_where,
             blind=blind, projected_w=None,
-            reason=(f"PEAK GUARD BLIND ({blind}) - the battery may not import "
-                    f"while the billed quarter cannot be measured; commanding no "
-                    f"charging (floor 0 W)"))
+            reason=(f"PEAK_GUARD_BLIND: {blind}. The battery may not charge "
+                    f"while this 15-minute period cannot be measured, so it "
+                    f"is asked for no charging, floor 0 W"))
 
     projected = float(projection.projected_w)
     if batt_w is None:
@@ -794,17 +808,18 @@ def decide(projection, *, batt_w, cap_w, reading, achievable_w, soc, soc_floor,
             ceiling_from=from_where, projected_w=projected, excess_w=ex,
             wanted_w=wanted, floor_limited=True, soc=soc, soc_floor=soc_floor,
             soc_floor_reason=denied,
+            # UX-10: plain sentences, every figure kept (test_messages.py
+            # part 6). The code is one token, so it is not read as shouting.
             reason=(
-                f"PEAK GUARD FLOOR-LIMITED: the quarter projects "
-                f"{projected:.0f} W against a {ceiling:.0f} W ceiling "
-                f"({from_where}) and {wanted:+.0f} W of discharge would hold "
-                f"it, but {denied}"
-                + ("" if soc is None else f" ({float(soc):.0f} %")
+                f"PEAK_GUARD_FLOOR_LIMITED: this 15-minute period heads for "
+                f"{projected:.0f} W against a {ceiling:.0f} W limit "
+                f"({from_where}), and {wanted:+.0f} W from the battery would "
+                f"hold it. But {denied}"
+                + ("" if soc is None else f", at {float(soc):.0f} %")
                 + ("" if soc is None or soc_floor is None
-                   else f" vs {float(soc_floor):.0f} %")
-                + ("" if soc is None else ")")
-                + " - commanding no forced discharge, so THIS QUARTER WILL GO "
-                  "OVER THE CEILING. Charging stays blocked (floor 0 W)"))
+                   else f" against {float(soc_floor):.0f} %")
+                + ", so no forced discharge and no charging, and this period "
+                  "will go over the limit"))
 
     floor = min(wanted, ceil_top)
     saturated = floor < wanted
@@ -813,13 +828,154 @@ def decide(projection, *, batt_w, cap_w, reading, achievable_w, soc, soc_floor,
         blind=None, projected_w=projected, excess_w=ex, wanted_w=wanted,
         saturated=saturated, soc=soc, soc_floor=soc_floor,
         reason=(
-            f"PEAK GUARD: quarter projects {projected:.0f} W against a "
-            f"{ceiling:.0f} W ceiling ({from_where}) with "
+            f"PEAK_GUARD: this 15-minute period heads for {projected:.0f} W "
+            f"against a {ceiling:.0f} W limit ({from_where}), with "
             f"{QUARTER_S - projection.elapsed_s:.0f} s left, so {ex:.0f} W must "
-            f"come off the meter; battery measured {float(batt_w):+.0f} W, "
-            f"floor {floor:+.0f} W"
-            + (f" - SATURATED, {wanted:+.0f} W was needed and the inverter can "
-               f"only give {ceil_top:.0f} W" if saturated else "")))
+            f"come off the meter. The battery measured {float(batt_w):+.0f} W "
+            f"and is asked for {floor:+.0f} W"
+            # Saturated means floor == ceil_top: the ask IS the most the
+            # inverters give, so one clause says both.
+            + (f", the most the inverters give, but {wanted:+.0f} W was needed"
+               if saturated else "")))
+
+
+def charge_headroom_w(decision) -> float | None:
+    """SAFETY-45. The hardest this SITE may charge without putting the billed
+    quarter over the ceiling, in W, positive - or None when nothing measured it.
+
+    THE ONE PLACE THIS QUESTION IS ANSWERED, and it is public for the reason
+    `discharge_permitted()`, `shaping_suspended()`, `guard_state()` and
+    `looks_frozen()` are: the check that grades it has to assert on THE SHIPPED
+    EXPRESSION, and a predicate transcribed into its own test is one copy plus a
+    future disagreement about what the check means.
+
+    ------------------------------------------------------------------------
+    THE DEFECT IT PREVENTS, AND IT IS NOT A NEW IDEA IN THIS REPOSITORY
+
+    `control.maintenance_charge_floor()` already caps MAINTENANCE charging at
+    "the headroom left under the site's cap", and its docstring says why in
+    words this card only has to widen:
+
+        "A maintenance charge is the only thing this system does that is big
+        enough and long enough to set that peak, so it is capped by the
+        headroom left under the site's cap."
+
+    ⚠️ THAT SENTENCE STOPPED BEING TRUE WHEN OPT-04 LANDED. Price arbitrage is a
+    SECOND thing that is big enough and long enough - it commands `max_w` for a
+    whole tariff interval, deliberately, against the meter - and it was given no
+    such cap. Measured on TEST-23 stage 3's closed rig at the shipped
+    `peak_cap_w: 3500` / `max_w: 2000`: 28 charge onsets in one hour, mean period
+    131 s, grid swinging -456 <-> +3200 W, on any house drawing over 1500 W in
+    the cheapest quarter. §10.2: "an EMS that oscillates is worse than no EMS,
+    both for hardware wear and - per §9.1 - for the peak it is trying to avoid."
+
+    ⚠️ AND IT IS THE **MEASURED** GUARD, NOT `peak_forecast_entity`.
+    `maintenance_charge_floor()` sizes itself from the forecast sensor, which is
+    OPTIONAL and empty on a default install - the exact hole SAFETY-25 had to
+    close in `shaping_suspended()`, where a suspension gated on the forecast
+    alone could not fire on the very site that needed it. This number comes off
+    `decide()`, which runs wherever P1 does.
+
+    ------------------------------------------------------------------------
+    WHERE THE NUMBER COMES FROM: IT IS `wanted_w`, READ IN THE OTHER DIRECTION
+
+    `decide()` already computes
+
+        wanted = batt_w + excess = (the offtake there would be with the battery
+                 at zero) - (the level this quarter can still afford)
+
+    as the battery DISCHARGE that would land the quarter exactly on the ceiling.
+    A negative `wanted` is not "nothing to say" - it is a permitted CHARGE of
+    `-wanted` watts, and throwing it away is SAFETY-45's whole defect. So this
+    function invents no arithmetic; it reads the sign the guard already had.
+
+    ⚠️ AND THE QUANTITY IS INVARIANT IN THE BATTERY, WHICH IS WHY SIZING A TRADE
+    TO IT CANNOT OSCILLATE. Raise the charge by dW and the meter rises by dW, so
+    `excess` rises by exactly dW while `batt_w` falls by dW: `wanted` does not
+    move. It is a FEED-FORWARD number - a function of the house, the ceiling and
+    the seconds already banked - so consuming it adds no feedback path around the
+    plant. The fixed point is `charge = ceiling - load`, with the meter sitting
+    ON the ceiling and `wanted` parked at `load - ceiling`, a whole `ceiling -
+    load` clear of the engagement boundary rather than chattering across it.
+
+    ⚠️ AND A QUARTER BOUNDARY DOES NOT HAND IT BACK AT FULL POWER, WHICH IS THE
+    OTHER HALF OF SAFETY-45 AND IS NOT THE SAME CLAIM AS "IT DOES NOT CHANGE".
+    It DOES change - it is `(900 / remaining) * (ceiling - projected)`, so it is
+    largest in the last seconds of a block and collapses at the boundary. What
+    matters is WHAT IT COLLAPSES TO: at `elapsed = 0` the projection IS the held
+    level, so the answer is `ceiling - (load - pv)` - the house and the cap, and
+    nothing else. A trade refused at 14:59 therefore resumes at 15:00 at the rate
+    the new quarter can afford, not at `max_w`, and §10.1's answer survives the
+    boundary because the arithmetic does: no timer, no backoff constant, no state
+    carried between calls.
+
+    ⚠️ AND THE AMPLIFICATION IS BOUNDED IN ITS EFFECT, NOT MERELY LARGE. Hold a
+    charge of exactly this size for the rest of the block and the block's average
+    lands on `ceiling` EXACTLY, wherever in the block it started:
+
+        (acc + (held + headroom) * remaining) / 900
+            = projected + (900/remaining) * (ceiling - projected) * remaining/900
+            = ceiling
+
+    so 162 kW of headroom with 5 s left and 900 W of it with the whole quarter to
+    go are the same statement about the bill. `test_peakguard.py` part 13 sweeps
+    that identity across the block rather than arguing it here.
+
+    ------------------------------------------------------------------------
+    THE THREE ANSWERS
+
+    `None`  nothing measured it: the guard never ran (`meter_source: off`), or
+            it ran with no battery reading to size a floor from, or the block
+            had no seconds left to influence. ⚠️ None IS NOT UNLIMITED. A caller
+            that treats it as "charge away" is `arbitrage.guard_state()`'s
+            collapse of None into False, one layer down - a strategy creating
+            the billed quantity while nothing measures the quarter it lands in.
+    `0.0`   measured, and the answer is no charging: the guard is BLIND (its
+            claim already says so at `floor 0 W` and this agrees with it rather
+            than restating it), or it is holding and `wanted >= 0`.
+    `> 0`   the watts a charge may pull this cycle.
+
+    ⚠️ HOLDING IMPLIES ZERO, BY CONSTRUCTION AND NOT BY COINCIDENCE. Every state
+    that files a claim with `engaged=True` has `wanted > 0`, `wanted is None` or
+    `blind`, so this answers 0.0 or None there and can never hand a strategy
+    permission the guard's own `lo` is at that instant refusing.
+
+    ------------------------------------------------------------------------
+    ⚠️ WHY THIS IS A SIZING AND NOT A CLAIM, AND DO NOT "SIMPLIFY" IT INTO ONE
+
+    The obvious tidier answer is to delete `decide()`'s `wanted <= 0` gate and
+    let it file `lo = wanted` unconditionally - a NEGATIVE floor, meaning "you
+    may charge, but no harder than this". The arithmetic is identical, it is
+    continuous, and it would bind every claimant rather than only arbitrage. It
+    was measured, considered and REJECTED, and the reason is not style:
+
+      * `main.py`'s cheap-window maintenance charge files
+        `Claim.limit("maintenance", P_MAINT_SHAPE, hi=-floor)` - a NEGATIVE `hi`.
+        arbiter.py clause 2 applies EVERY limit at or above the winner's priority
+        and takes the most restrictive, with no notion of one limit out-ranking
+        another. A peak `lo = -300 W` against a shaping `hi = -1000 W` is
+        `lo > hi`: a CONTRADICTION, which resolves to 0 W - the battery PARKED,
+        in the one quarter of the month that sets the bill. That is the exact
+        failure `shaping_suspended()` exists to prevent, and the only way to
+        close it would be to key that suppression on "a claim exists", which on
+        every site this card is about suspends the maintenance charge-only
+        shaping PERMANENTLY.
+      * and it would change what `engaged` MEANS at five call sites outside this
+        module - `arbitrage.guard_state()`, `shaping_suspended()`, `claim()`,
+        main.py's edge-logged action line and main.py's status row - each of
+        which today reads it as "the guard is HOLDING".
+
+    `control.maintenance_charge_floor()` is a sizing and not a limit for the same
+    reason, which is why this is the shape that already fits.
+    DECISIONS/SAFETY-45-sizing-the-trade.md §2b carries the full argument.
+    """
+    if decision is None:
+        return None
+    if decision.blind:
+        return 0.0
+    if decision.wanted_w is None:
+        return None
+    return max(0.0, -float(decision.wanted_w))
 
 
 def shaping_suspended(decision, peak_forecast_w, cap_w) -> bool:

goodwe_controller/app/price.py

@@ -150,9 +150,10 @@ from enum import Enum
 from textwrap import dedent
 from urllib.parse import urlencode
 
+from . import messages
 from .custom_formula import (
-    FormulaInvalid, PREVIEW_HOURS, parse_price_formula, preview_lines,
-    price_eur_kwh, to_resolution)
+    EXPORT_FORMULA_OPTION, FormulaInvalid, PREVIEW_HOURS, parse_export_formula,
+    parse_price_formula, preview_lines, price_eur_kwh, to_resolution)
 
 _LOG = logging.getLogger("goodwe.price")
 
@@ -818,6 +819,69 @@ def plan_is_provisional(read: PriceRead) -> bool:
 # Options: what a plugin may see, and what it may not
 # --------------------------------------------------------------------------- #
 
+# --------------------------------------------------------------------------- #
+# TARIFF-18: what `price_taxes_eur_kwh` IS MADE OF
+# --------------------------------------------------------------------------- #
+
+# ⚠️ THE DEFECT THIS TABLE PREVENTS IS THE ONE THE SHIPPED 0.06 WAS: A NUMBER
+# NOBODY COULD SOURCE. 0.06 EUR/kWh is roughly HALF the real Flemish non-energy
+# figure, and because no reader could see what it was made of there was nothing
+# to argue with. Every row below is one line of the Eneco residential card for
+# Flanders, September 2026, INCLUDING 6 % VAT, converted from the c EUR/kWh the
+# card prints to the EUR/kWh this option takes. `price_taxes_eur_kwh`'s default
+# is their sum, and test_price.py section 1b re-adds them and refuses a default
+# that is not exactly that.
+#
+# ⚠️ THIS IS A PER-DSO FIGURE, AND IT IS THE DISTRIBUTION ROW THAT MOVES. Across
+# the eight Fluvius DSOs that row runs 5,28 c EUR/kWh (Midden-Vlaanderen) to
+# 6,70 (West), so the all-in Flemish total runs about 0.117 to 0.131 EUR/kWh.
+# A site outside Antwerpen should type its own total; the other two rows are
+# Flanders-wide and do not move with the DSO.
+#
+# ⚠️ AND THE DEFAULT SITS NEAR THE LOW END OF THAT BAND ON PURPOSE, BECAUSE THE
+# TWO ERROR DIRECTIONS ARE NOT SYMMETRIC. This scalar is a LEVEL component: it
+# cancels exactly in `max - min` and cannot move which hour is cheapest
+# (test_price.py 16b measures that as a family). The one DECISION it reaches is
+# §17's negative-price guard in arbitrage.py, which tests the ABSOLUTE all-in
+# price of the sell hour. A figure set too HIGH carries a genuinely negative
+# hour up above zero, and the add-on exports into paid-for disposal - the exact
+# case §17 exists to refuse. A figure set too LOW only declines a trade that
+# would have paid. So where a default must stand in for eight different DSOs,
+# it belongs at the bottom of the band and not in the middle of it.
+#
+# ⚠️ `energiebijdrage` IS ZERO, AND IT IS A ROW HERE RATHER THAN AN ABSENCE.
+# "Vanaf 1 augustus 2026 bedraagt de energiebijdrage 0 EUR/MWh" - it was merged
+# into the bijzondere accijns. Anyone re-deriving this total from a guide
+# written before that date will find a separate energiebijdrage line and add it
+# on top of an accijns that already contains it. The zero row is here so that
+# the double-count is visible as a decision rather than as an omission.
+FLEMISH_TAXES_COMPONENTS_EUR_KWH = (
+    ("Fluvius distribution, Antwerpen", 0.0535),
+    ("Bijzondere accijns, 'Alle verbruik' - no volume bands", 0.04876),
+    ("Bijdrage groene stroom en WKK Vlaanderen", 0.0151),
+    ("Energiebijdrage - 0 EUR/MWh since 2026-08-01, inside the accijns", 0.0),
+)
+
+# ⚠️ TARIFF-18, AND IT IS NOT HOUSEKEEPING - IT DECIDES WHICH CONFIGS START.
+# TARIFF-17's rung in validate.py refuses a site that sets `price_taxes_profile`
+# AND leaves `price_taxes_eur_kwh` at something other than the shipped default,
+# because the table wins and the scalar would decide nothing. It compares
+# against the DEFAULT rather than against presence, because the Supervisor sets
+# `App.options = deepmerge(config.yaml defaults, stored options)` and a saved
+# blob therefore carries every schema key whether the operator typed it or not
+# (measured: the reference install's export is 70 of 71 keys - CHANGELOG 0.9.0,
+# `tools/supervisor_selfapi_probe.py` §D).
+#
+# So moving the default turns a previously ACCEPTED configuration into
+# `SystemExit(78)`. A site that stored 0.06 - which is every install that has
+# ever saved its configuration - and that also carries a taxes table would stop
+# starting on the upgrade, over a number it never typed and that decides
+# nothing. That refusal would be TRUE and USELESS: the rung's subject is a
+# number the OPERATOR typed, and a superseded shipped default is not one. It
+# still reads as "untouched" here, and the rung's sentence names both figures.
+SUPERSEDED_TAXES_DEFAULTS_EUR_KWH = (0.06,)     # TARIFF-02 .. TARIFF-17
+
+
 # ⚠️ CFG-03, AND HOW THIS TICKET AVOIDS WIDENING IT. Option defaults in this
 # add-on already live in three places - config.yaml, main.py's `o.get(k, X)`
 # fallbacks, and a dataclass default - held apart only by a tripwire in
@@ -836,7 +900,9 @@ def plan_is_provisional(read: PriceRead) -> bool:
 PRICE_OPTION_DEFAULTS = {
     "price_provider": "off",
     "price_markup_eur_kwh": 0.03,      # §14 tariffs.energy_price.markup_eur_kwh
-    "price_taxes_eur_kwh": 0.06,       # §14 tariffs.energy_price.taxes_eur_kwh
+    # TARIFF-18: the sum of FLEMISH_TAXES_COMPONENTS_EUR_KWH above, to the
+    # card's own last digit. §14 tariffs.energy_price.taxes_eur_kwh.
+    "price_taxes_eur_kwh": 0.11736,
     "export_price_eur_kwh": 0.04,      # §14 tariffs.export_price_eur_kwh (AC4)
     "price_csv_path": "/share/goodwe_prices.csv",
     "price_feed_url": "",
@@ -851,6 +917,18 @@ PRICE_OPTION_DEFAULTS = {
     # test_price.py section 1. A second defaults dict in the new module would be
     # a fourth place option defaults live, which is exactly the open ticket.
     "static_profile": "",
+    # TARIFF-17. A JSON object in `static_profile`'s OWN period grammar whose
+    # per-period `eur_per_kwh` is the TAXES COMPONENT for that band, not an
+    # all-in price; "" is unset and the scalar above decides. Parsed and
+    # validated by app/static_tariff.py (`parse_taxes_profile`), refused at
+    # startup by validate.py - the `static_profile` precedent exactly, and here
+    # for the same CFG-03 reason: this dict is the ONE in-code mirror of
+    # config.yaml.
+    #
+    # ⚠️ IT IS IN FRAMEWORK_KEYS. A plugin that could read this could add the
+    # taxes a second time, per hour, which is the double-counting defect trap 1
+    # exists to refuse - wearing a period table instead of a scalar.
+    "price_taxes_profile": "",
     # TARIFF-15. A JSON object carrying ONE contract's two coefficients, the
     # units they are printed in, its VAT rate and the card figures the add-on
     # grades them against; "" is unset. Parsed and validated by
@@ -858,6 +936,20 @@ PRICE_OPTION_DEFAULTS = {
     # `static_profile` precedent exactly, and here for the same CFG-03 reason:
     # this dict is the ONE in-code mirror of config.yaml.
     "price_formula": "",
+    # TARIFF-16. The INJECTION leg, in `price_formula`'s OWN grammar and read
+    # by `custom_formula.parse_export_formula()` - the same parser with its
+    # option name as an argument, so a second unit table and a second unknown-
+    # key rule do not exist to diverge. "" is unset and the scalar
+    # `export_price_eur_kwh` above decides, which is every site today.
+    #
+    # ⚠️ IT IS IN FRAMEWORK_KEYS, for the reason the scalar is: a CONSUMPTION
+    # plugin that could read an injection curve could fold it into a
+    # consumption price, and nothing downstream could tell.
+    #
+    # ⚠️ AND IT LIVES HERE RATHER THAN IN custom_formula.py FOR CFG-03's SAKE,
+    # exactly as `price_formula` and `price_taxes_profile` do: this dict is the
+    # ONE in-code mirror of config.yaml.
+    "price_export_formula": "",
     # OPT-04. §10.1 priority 3, and §14's `optimizer.cycle_cost_threshold_eur`.
     #
     # ⚠️ THEY LIVE HERE FOR CFG-03's SAKE, exactly as `static_profile` does, and
@@ -884,6 +976,19 @@ PRICE_OPTION_DEFAULTS = {
 # that can double-count, so `PluginOptions` refuses them by name. Trap 1.
 FRAMEWORK_KEYS = frozenset({
     "price_markup_eur_kwh", "price_taxes_eur_kwh", "export_price_eur_kwh",
+    # TARIFF-17. The hour-varying spelling of `price_taxes_eur_kwh`, and it
+    # belongs here for the same reason the scalar does: it is a component the
+    # FRAMEWORK adds exactly once, by `caps.adds`. `BANNED_IN_PLUGIN_CODE` is
+    # derived from this set, so `code_leaks()` refuses a plugin that names it
+    # without anything else being edited.
+    "price_taxes_profile",
+    # TARIFF-16. The hour-varying spelling of `export_price_eur_kwh`, and it
+    # belongs here for the same reason the scalar does: a plugin that could
+    # read an INJECTION curve could fold it into the CONSUMPTION series it
+    # emits, and `assemble()` has no way to notice a component that arrived
+    # inside a RawPoint. `BANNED_IN_PLUGIN_CODE` is derived from this set, so
+    # `code_leaks()` refuses a plugin that names it with nothing else edited.
+    EXPORT_FORMULA_OPTION,
 })
 
 
@@ -997,28 +1102,103 @@ def export_price_eur_kwh(opts: dict) -> float:
     consumption is at 6% - so it is a second per-contract formula, not a second
     copy of the first.
 
-    ⚠️ TARIFF-15 LANDED THE EVALUATOR AND DID NOT LAND THIS CURVE, and the
-    difference is the point rather than an omission. `custom_formula` can now
-    express `B x index + A` exactly - it is what it exists for - but it is a
-    CONSUMPTION provider: it declares {ENERGY, MARKUP}, the framework adds the
-    consumption taxes, and an injection leg carries its OWN coefficients
-    (Eneco: 0,102 consumption against 0,100 injection) and its own VAT
-    treatment (injection is exempt; consumption is at 6%). Pointing this
-    scalar at that machinery would mean pricing an injection curve with a
-    consumption card, which is the wrong-card defect the card self-check
-    exists to refuse. So until the injection card lands this scalar remains a
-    SIMPLIFICATION an operator enters by hand - an average of what they are
-    actually paid - and not a reflection of the market. When it does land, an
-    injection curve gets a `PriceProvider` of its own and this scalar becomes
-    its FIXED-product default; the seam is already the right shape for that.
+    ⚠️ TARIFF-16 LANDED THE INJECTION LEG, AND THIS FUNCTION IS UNCHANGED. The
+    curve lives in `price_export_formula` and is read by `export_formula()`
+    below; this reader still answers the FLAT injection price, still from one
+    option, still with no formula anywhere in its arithmetic. That is the
+    arrangement this docstring predicted before either existed - "an injection
+    curve gets a `PriceProvider` of its own and this scalar becomes its
+    FIXED-product default" - and it is why a site with a flat injection price
+    sees nothing change: `price_export_formula` ships "", `export_price_at()`
+    falls through to this function, and this function's body is byte-identical
+    to the one TARIFF-02 shipped.
 
     ⚠️ It is NOT reachable from a plugin: `export_price_eur_kwh` is in
     FRAMEWORK_KEYS, so a consumption plugin cannot quietly fold an injection
-    price into a consumption price.
+    price into a consumption price. `price_export_formula` is in the same set
+    for the same reason.
+
+    ⚠️ AND NOTHING IN THIS ADD-ON READS EITHER ONE TO TAKE A DECISION.
+    `arbitrage.py` prices the sell side as DISPLACED IMPORT and says so in its
+    own comment; both hours it compares are all-in consumption prices. This
+    reader has no caller under `app/` and neither does `export_price_at()`.
+    They are what an operator is shown and what a future export-aware strategy
+    would call - not a number any trade turns on today.
     """
     return float(price_option(opts, "export_price_eur_kwh"))
 
 
+def export_formula(opts: dict):
+    """The configured `price_export_formula` as a `FormulaSpec`, or None.
+
+    TARIFF-16. Raises `custom_formula.FormulaInvalid` on a malformed leg - and
+    ⚠️ THAT EXCEPTION IS NOT MEANT TO REACH A RUNNING SITE, by the rule
+    `taxes_profile()` states above and `static_profile` established:
+    validate.py parses the same option at STARTUP and refuses to start on it,
+    because a formula that only fails when something reads it is a defect
+    discovered at the worst possible moment and §11.4 makes every price
+    defect quiet.
+
+    ⚠️ THE PARSE IS THE SAME ONE THE CONSUMPTION LEG GETS. There is no second
+    parser, no second unit table and no second resolution rule -
+    `parse_export_formula()` is `parse_price_formula()` with its `option`
+    argument moved, so every refusal an operator can hit on this leg is a
+    refusal that already had checks over it.
+    """
+    return parse_export_formula(price_option(opts, EXPORT_FORMULA_OPTION))
+
+
+def export_price_at(opts: dict, index_eur_per_mwh: float) -> float:
+    """What the site is PAID for one exported kWh at one index value, EUR/kWh.
+
+    THE SEAM, AND ITS HONEST SCOPE. This is the one function a future
+    export-aware strategy calls, and it has NO CALLER UNDER `app/` today -
+    stated here rather than implied, because the add-on takes no decision on an
+    injection price (see `export_price_eur_kwh()` above and `arbitrage.py`'s
+    accounting-basis comment). What it buys now is that OPT-06 and anything
+    after it inherit a shape the market fits, instead of a scalar that cannot
+    hold its own factor, a negative offset, or a VAT rate different from the
+    consumption leg's.
+
+    ⚠️ THE FLAT PATH IS THE FALLTHROUGH AND IT IGNORES THE INDEX, which is
+    CORRECT rather than a simplification: a site with a flat injection price is
+    paid the same for every kWh whatever the market did, and that is what the
+    scalar means. With `price_export_formula` empty - every site today - this
+    returns exactly `export_price_eur_kwh(opts)` for every index.
+
+    ⚠️ A NEGATIVE ANSWER IS A REAL ANSWER. Eneco's `0,1 x BELPEX-H - 1,188` is
+    below zero for any BELPEX-H under 11,88 EUR/MWh, which is the middle of a
+    sunny day and precisely when a PV household exports. Nothing here floors
+    it: a caller that silently clamped it to zero would hide the hours in which
+    exporting COSTS money, which is the one thing an injection price is for.
+    """
+    spec = export_formula(opts)
+    if spec is None:
+        return export_price_eur_kwh(opts)
+    return price_eur_kwh(spec, index_eur_per_mwh)
+
+
+def taxes_profile(opts: dict):
+    """The configured `price_taxes_profile` as a period table, or None.
+
+    TARIFF-17. Raises `static_tariff.ProfileInvalid` on a malformed table - and
+    ⚠️ THAT EXCEPTION IS NOT MEANT TO REACH A RUNNING SITE. validate.py parses
+    the same option at STARTUP and refuses to start on it, for the reason
+    `static_profile` is refused there: a table that only fails when a fetch
+    happens is a site that stops pricing at 03:00, and §11.4 turns that into a
+    quiet fallback nothing on the status page distinguishes from a healthy
+    fixed-tariff day. `load_prices()` still handles it, loudly, because a guard
+    whose only proof is "the other guard ran first" is not a guard.
+
+    ⚠️ THE IMPORT IS LAZY AND THE CYCLE IS THE REASON. `static_tariff.py`
+    imports this module at module scope; importing it back at module scope here
+    would make which file is imported first decide whether the add-on starts.
+    `sys.modules` makes the repeat cost a dict lookup.
+    """
+    from .static_tariff import parse_taxes_profile
+    return parse_taxes_profile(price_option(opts, "price_taxes_profile"))
+
+
 # --------------------------------------------------------------------------- #
 # The plugin interface
 # --------------------------------------------------------------------------- #
@@ -1135,8 +1315,8 @@ def code_leaks(cls) -> list:
         src = dedent(inspect.getsource(cls))
         tree = ast.parse(src)
     except (OSError, TypeError, IndentationError, SyntaxError) as e:
-        _LOG.warning("could not read %s's source for the framework-key scan "
-                     "(%s); the double-counting guard is NOT enforced for it",
+        _LOG.warning("Could not read the code of price source %s (%s), so its "
+                     "double-counting check is skipped.",
                      getattr(cls, "id", cls), e)
         return []
     for node in ast.walk(tree):
@@ -1274,9 +1454,8 @@ def _validate_raw(points, caps):
         if abs(p.eur_per_kwh) > MAX_PLAUSIBLE_EUR_KWH:
             raise SourceUnavailable(
                 f"point at {p.start.isoformat()} is {p.eur_per_kwh} EUR/kWh, "
-                f"beyond +-{MAX_PLAUSIBLE_EUR_KWH} - the usual cause is a feed "
-                f"in EUR/MWh being read as EUR/kWh, which is a factor of 1000 "
-                f"and would make every hour look like an emergency")
+                f"beyond +-{MAX_PLAUSIBLE_EUR_KWH}, so the feed is probably in "
+                f"EUR/MWh")
         u = p.start.astimezone(timezone.utc)
         if seen is not None and u <= seen:
             raise SourceUnavailable(
@@ -1286,23 +1465,68 @@ def _validate_raw(points, caps):
         seen = u
 
 
+def taxes_at(taxes, instant: datetime) -> float:
+    """The TAXES component at ONE instant. A scalar, or a period table.
+
+    TARIFF-17. THE DEFECT THIS EXISTS TO CLOSE, and it is a MISSING CAPABILITY
+    rather than a wrong constant: `price_taxes_eur_kwh` is additive and
+    identical every hour, so it cancels exactly out of `max - min` and cannot
+    move `min(firm, key=...)`. It is not a distortion - it is provably inert on
+    both quantities the optimiser reads. What was missing is anywhere for an
+    HOUR-VARYING non-energy component to live, and the Walloon and Brussels
+    DSOs bill one: ORES `dag 13,27 / nacht 7,39` c EUR/kWh, a 5,88 c gap whose
+    cheap band coincides with the cheap spot hours. Flattening it does not
+    shift the curve, it UNDERSTATES the spread and declines profitable cycles.
+    See DOCS.md "The three buckets".
+
+    ⚠️ DUCK-TYPED ON `price_at`, NOT ON `isinstance`. price.py must not import
+    static_tariff.py - static_tariff.py imports THIS module, and a module-level
+    cycle would make the import order load-bearing. `taxes_profile()` below is
+    the one place the real parser is reached, and it imports it lazily.
+
+    ⚠️ THE LOOKUP IS ON THE ~30 s PLANNING PATH through `assemble()`, so it
+    stays a linear scan over the two-to-four periods a Belgian tariff has
+    (`StaticProfile.at()`), with no parsing, no allocation and no I/O. A
+    malformed table never reaches here: validate.py refuses it at STARTUP.
+    """
+    at = getattr(taxes, "price_at", None)
+    if at is None:
+        return float(taxes)
+    return float(at(instant))
+
+
 def assemble(caps: ProviderCapabilities, raw, markup: float,
-             taxes: float) -> list:
+             taxes) -> list:
     """RawPoints -> canonical all-in PricePoints. THE ONLY PLACE MARKUP IS ADDED.
 
     Adds exactly `caps.adds` - the complement of what the plugin declared its
     source already contains. A plugin that publishes an all-in figure gets
     nothing added; a raw EPEX figure gets both.
+
+    ⚠️ `taxes` IS A SCALAR *OR* A PERIOD TABLE (TARIFF-17), AND IT IS EVALUATED
+    AT EACH POINT'S OWN INSTANT. Hoisting the lookup out of the loop - reading
+    it once and adding the same number to every point - is the mutation that
+    collapses the whole feature back into the LEVEL bucket: the assembled
+    series would still differ from the untaxed one by the right MAGNITUDE, and
+    the cheapest hour would be wrong. `test_price.py` section 24 is the check
+    that goes red for it, and it grades WHICH HOUR IS CHEAPEST rather than the
+    spread, because a spread-magnitude assertion passes on the hoisted version.
+
+    ⚠️ THE SCALAR PATH IS UNCHANGED, ARITHMETICALLY AND NOT ONLY IN INTENT.
+    `taxes_at()` on a float returns that float at every instant, and
+    `0.0 + markup` is exactly `markup` in IEEE 754 for every finite markup, so
+    a site on a scalar gets the identical bytes it got before this landed.
     """
-    add = 0.0
-    if Component.MARKUP in caps.adds:
-        add += float(markup)
-    if Component.TAXES in caps.adds:
-        add += float(taxes)
-    return [PricePoint(start=brussels(p.start),
-                       eur_per_kwh=round(p.eur_per_kwh + add, 6),
-                       provisional=bool(p.provisional))
-            for p in raw]
+    add_markup = float(markup) if Component.MARKUP in caps.adds else 0.0
+    wants_taxes = Component.TAXES in caps.adds
+    out = []
+    for p in raw:
+        local = brussels(p.start)
+        add = add_markup + (taxes_at(taxes, local) if wants_taxes else 0.0)
+        out.append(PricePoint(start=local,
+                              eur_per_kwh=round(p.eur_per_kwh + add, 6),
+                              provisional=bool(p.provisional)))
+    return out
 
 
 # --------------------------------------------------------------------------- #
@@ -1484,25 +1708,19 @@ def _points_from_columnar_json(body, expect_unit, scale,
     if len(times) != len(prices):
         raise SourceUnavailable(
             f"{COLUMNAR_TIME_KEY} has {len(times)} entries and "
-            f"{COLUMNAR_PRICE_KEY} has {len(prices)}; refusing to zip them. "
-            f"The short array would truncate the series silently, and a price "
-            f"series missing its last hours is one missing the evening peak - "
-            f"traded on as if complete, where no data at all would have "
-            f"switched arbitrage off (§11.4)")
+            f"{COLUMNAR_PRICE_KEY} has {len(prices)}, so the feed is cut short "
+            f"and none of it is used")
     unit = _columnar_unit(doc.get(COLUMNAR_UNIT_KEY, ""))
     if unit != _columnar_unit(expect_unit):
         raise SourceUnavailable(
             f"the feed reports {doc.get(COLUMNAR_UNIT_KEY)!r}, not "
-            f"{expect_unit!r}. This provider converts with a fixed factor of "
-            f"{scale}, so a changed unit is a factor of 1000 on every price "
-            f"with nothing downstream able to notice it")
+            f"{expect_unit!r}, so its prices cannot be converted")
     if doc.get("deprecated"):
         # Not a refusal: today's prices are still prices. But §11.4 makes a
         # dead feed look exactly like a quiet one, so the warning that the
         # source is going away has to be emitted while it still works.
-        _LOG.warning("the price feed reports deprecated=%r; it still answers, "
-                     "but this endpoint is scheduled to stop",
-                     doc.get("deprecated"))
+        _LOG.warning("The price feed says it will stop (deprecated=%r), "
+                     "though it still answers for now.", doc.get("deprecated"))
     out = []
     dropped = []
     for i, (t, v) in enumerate(zip(times, prices)):
@@ -1521,12 +1739,11 @@ def _points_from_columnar_json(body, expect_unit, scale,
         out.append(RawPoint(start=start, eur_per_kwh=float(v) * scale,
                             provisional=bool(provisional_default)))
     if dropped:
-        _LOG.warning("the feed published no price for %d of %d instants "
-                     "(index %s); those instants are left OUT of the series, "
-                     "never zero-filled - a missing hour is not a free hour",
-                     len(dropped), len(times),
+        _LOG.warning("The price feed gave no price for %d of %s, at index "
+                     "%s. Those are left out, not counted as free.",
+                     len(dropped), messages.count(len(times), "time"),
                      ", ".join(str(i) for i in dropped[:5])
-                     + (", ..." if len(dropped) > 5 else ""))
+                     + (" and more" if len(dropped) > 5 else ""))
     if not out:
         raise SourceUnavailable(
             f"the feed carried {len(times)} instants and a price for none of "
@@ -1572,16 +1789,16 @@ def dayahead_feed_url(plugin_id, opts, since, until, base, bzn) -> str:
     override = str(opts.get("price_feed_url") or "").strip()
     if override:
         _LOG.warning(
-            "price_feed_url is set, so %s is requesting %s exactly as "
-            "given and is adding NO date range to it. The public feed "
-            "answers a single Brussels day to a request that names no "
-            "range, and every hour past that day is then carried forward "
-            "from yesterday's profile and flagged provisional - §8.3 "
-            "drops provisional hours from the trade set, so arbitrage "
-            "would never see tomorrow as firm. Clear price_feed_url to "
-            "let this plugin ask for the %s..%s it was given.",
+            "price_feed_url is set, so %s asks for %s as given, and "
+            "tomorrow's prices may stay provisional. Clear it to ask for %s "
+            "to %s.",
             plugin_id, override, *(d.isoformat()
                                    for d in brussels_date_range(since, until)))
+        _LOG.debug(
+            "The public feed answers one Brussels day to a request that names "
+            "no range. Every later hour is then copied from yesterday and "
+            "marked provisional, and §8.3 leaves provisional hours out of "
+            "trading.")
         return override
     first, last = brussels_date_range(since, until)
     return dated_feed_url(base, bzn=bzn, start=first.isoformat(),
@@ -1787,11 +2004,9 @@ class CustomFormula(PriceProvider):
             raise SourceUnavailable(f"price_formula: {e}")
         if spec is None:
             raise SourceUnavailable(
-                "price_provider is 'custom_formula' but price_formula is "
-                "empty, so there are no coefficients to price anything with. "
-                "validate.py refuses this configuration at startup; reaching "
-                "it here means the options blob changed under a running "
-                "add-on")
+                "“Dynamic price source” (price_provider) is 'custom_formula', "
+                "but “Your own tariff formula” (price_formula) is empty. "
+                "Restart the add-on to check the settings again")
         url = dayahead_feed_url(self.id, opts, since, until,
                                 self.FEED_BASE, self.BZN)
         check_egress(url, self.capabilities())
@@ -1867,8 +2082,8 @@ def _emit_startup_preview(plugin, pid: str, points) -> None:
     try:
         lines = list(plugin.startup_preview(points))
     except Exception as e:                                    # noqa: BLE001
-        _LOG.warning("%s's startup preview raised (%s: %s); prices are "
-                     "unaffected - this is a log line, not a decision",
+        _LOG.warning("%s could not show its start-up preview (%s: %s). Prices "
+                     "are not affected.",
                      pid, type(e).__name__, e)
         return
     for line in lines:
@@ -1892,23 +2107,48 @@ async def load_prices(opts: dict, since: datetime, until: datetime,
     pid = provider_id(opts)
     if not provider_configured(opts):
         return PriceRead.no_data(
-            "no price provider configured (price_provider is 'off'); "
-            "§11.4: static profile, plan provisional, no arbitrage")
+            "no price feed is set (price_provider is 'off'), so the fixed "
+            "tariff is used, the plan is estimated and there is no trading")
     cls = PROVIDERS.get(pid)
     if cls is None:
         return PriceRead.no_data(
-            f"unknown price provider {pid!r}; shipped: "
+            f"unknown price provider {pid!r}. The known ones are "
             f"{', '.join(sorted(PROVIDERS))}")
 
     caps = cls.capabilities()
     markup = float(price_option(opts, "price_markup_eur_kwh"))
-    taxes = float(price_option(opts, "price_taxes_eur_kwh"))
+
+    # ⚠️ TARIFF-17: THE TABLE WINS OVER THE SCALAR, AND validate.py REFUSES THE
+    # CASE WHERE BOTH SAY SOMETHING. Two writers of one quantity, one of which
+    # silently loses, is the shape validate.py exists to refuse - so the
+    # precedence here is only ever exercised on a configuration that has
+    # already been accepted, and it is spelled out rather than left implicit.
+    taxes_key = "price_taxes_eur_kwh"
+    try:
+        table = taxes_profile(opts)
+    except Exception as e:                                    # noqa: BLE001
+        # Not silent, and not a traceback into the 30 s tick. validate.py
+        # should have refused this at startup; if the add-on is running with it
+        # anyway, the operator is told which key and what is wrong with it.
+        _LOG.error("price_taxes_profile cannot be used (%s: %s), so no taxes "
+                   "are added to this price update. Fix the table or clear it.",
+                   type(e).__name__, e)
+        _LOG.debug("price_taxes_eur_kwh is not used instead, because a "
+                   "silently different tax basis is the fault this setting "
+                   "exists to remove.")
+        return PriceRead.no_data(
+            f"price_taxes_profile cannot be used: {e}")
+    if table is not None:
+        taxes = table
+        taxes_key = "price_taxes_profile"
+    else:
+        taxes = float(price_option(opts, "price_taxes_eur_kwh"))
 
     # ⚠️ Not a refusal, but not silent either. A plugin whose feed is already
     # all-in ignores these two numbers, and an operator who typed them has every
     # reason to believe they took effect.
     ignored = [n for c, n, v in ((Component.MARKUP, "price_markup_eur_kwh", markup),
-                                 (Component.TAXES, "price_taxes_eur_kwh", taxes))
+                                 (Component.TAXES, taxes_key, taxes))
                if c not in caps.adds and v]
     if ignored:
         _LOG.warning("%s publishes a figure that already contains %s, so the "

goodwe_controller/app/price_forecast.py

@@ -164,6 +164,7 @@ from dataclasses import dataclass
 from datetime import datetime, timedelta, timezone
 from enum import Enum
 
+from . import messages
 from .maintenance import CHARGE_TIMEOUT_MIN, DRAIN_TIMEOUT_MIN
 from .price import PricePoint, PriceRead, _Outcome, brussels
 
@@ -411,13 +412,14 @@ def fill_from_yesterday(read: PriceRead, *, yesterday: PriceRead,
 
     if not out:
         reason = read.match(
-            series=lambda r: (f"the {len(r.points)} published hours all fall "
-                              f"outside {since.isoformat()}..{until.isoformat()}"),
+            series=lambda r: (f"all {messages.count(len(r.points), 'published price')} "
+                              f"fall outside {messages.when(brussels(since))} to "
+                              f"{messages.when(brussels(until))}"),
             no_data=lambda r: r.reason)
         return PriceRead.no_data(
-            f"§8.3 carry-forward produced no hours: {reason}, and yesterday's "
-            f"profile has nothing to fill them with either. §11.4 applies: "
-            f"static profile, plan provisional, no arbitrage")
+            f"no hours could be filled from yesterday's prices: {reason}. So "
+            f"the fixed tariff is used, the plan is estimated and there is no "
+            f"trading")
 
     _audit(out, published)
     carried = sum(1 for p in out if _utc_hour(p.start) not in published)
@@ -431,10 +433,11 @@ def fill_from_yesterday(read: PriceRead, *, yesterday: PriceRead,
         # hours" about a 48-hour horizon. The fill's unit is the HOUR and the
         # feed's is the POINT; nothing derived from one answers for the other.
         total_h = len({_utc_hour(p.start) for p in out})
-        _LOG.info("§8.3: %d of %d hours carried forward from yesterday's "
-                  "profile and flagged provisional; the feed published %d "
-                  "points over the other %d hours",
-                  carried, total_h, len(out) - carried, total_h - carried)
+        _LOG.info("%d of %s use yesterday's prices, marked as estimated. "
+                  "The feed published %s over the other %s.",
+                  carried, messages.count(total_h, "hour"),
+                  messages.count(len(out) - carried, "price"),
+                  messages.count(total_h - carried, "hour"))
 
     product = read.match(series=lambda r: r.product,
                          no_data=lambda _r: yesterday.product)
@@ -525,8 +528,8 @@ class _Permitted(Gate):
                 "one rule this type has.")
         self.action = action
         self.hours = pts
-        self.words = (f"{action.name} permitted on {len(pts)} firm hours "
-                      f"({pts[0].start.isoformat()} ..)")
+        self.words = (f"allowed on {messages.count(len(pts), 'published price')} "
+                      f"from {messages.when(brussels(pts[0].start))}")
 
 
 class _Blocked(Gate):
@@ -570,8 +573,8 @@ def price_permits(read: PriceRead, now: datetime,
     return read.match(
         series=lambda r: _walk(r, hours, action),
         no_data=lambda r: Gate.block(
-            f"{action.name} is gated on a price and there is no price data: "
-            f"{r.reason}. §11.4 - and a missing price is not a cheap one"))
+            f"{action.name} needs a price and there is none: {r.reason}. A "
+            f"missing price is not a cheap one"))
 
 
 def _walk(series, hours, action) -> Gate:
@@ -579,19 +582,18 @@ def _walk(series, hours, action) -> Gate:
     for u in hours:
         if not series.covers(u):
             return Gate.block(
-                f"{action.name} commits {action.commits_h:g} h from "
-                f"{hours[0].isoformat()} and no price covers "
-                f"{u.isoformat()}. An hour outside the series is an hour with "
-                f"no price (§11.4 for that hour), not a free one")
+                f"{action.name} needs prices for {action.commits_h:g} hours "
+                f"from {messages.when(brussels(hours[0]))}, and no price "
+                f"covers {messages.when(brussels(u))}. An hour with no price "
+                f"is not a free one")
         p = series.at(u)
         if p.provisional:
             return Gate.block(
-                f"{action.name} commits {action.commits_h:g} h from "
-                f"{hours[0].isoformat()} and {u.isoformat()} is PROVISIONAL - "
-                f"carried from yesterday's profile or standing in for a dead "
-                f"feed. §8.3: no irreversible action may be taken on a "
-                f"provisional price. It becomes available when the day-ahead "
-                f"print lands (~14-16 h CET, §5.4)")
+                f"{action.name} needs prices for {action.commits_h:g} hours "
+                f"from {messages.when(brussels(hours[0]))}, and the price for "
+                f"{messages.when(brussels(u))} is only estimated. It can start "
+                f"once the day-ahead prices are published, around 14:00 to "
+                f"16:00")
         pts.append(p)
     return Gate.permit(action, pts)
 
@@ -622,5 +624,6 @@ def _go(maint, now, gate) -> Gate:
 
 
 def _no(gate) -> Gate:
-    _LOG.warning("irreversible action refused - %s", gate.reason)
+    _LOG.warning("An action that cannot be undone does not start: %s.",
+                 gate.reason)
     return gate

goodwe_controller/app/price_history.py

@@ -186,8 +186,9 @@ import json
 import logging
 import os
 import tempfile
-from datetime import datetime, timedelta, timezone
+from datetime import date, datetime, timedelta, timezone
 
+from . import messages
 from .price import PricePoint, PriceProduct, PriceRead, brussels
 from .price_forecast import fill_from_yesterday
 
@@ -345,8 +346,19 @@ def _row_of(day: str, points: int, hours: int) -> str:
     whole day to carry, and that is the HOUR figure; the point count says how
     finely it is priced. Neither answers for the other.
     """
-    return (f"{day} ({points} point{'' if points == 1 else 's'} "
-            f"over {hours} h)")
+    # UX-10: the day as the page writes dates ("26 Sep"), not ISO.
+    return (f"{points} price{'' if points == 1 else 's'} over {hours} "
+            f"hour{'' if hours == 1 else 's'} for {day_words(day)}")
+
+
+def day_words(day) -> str:
+    """`'2026-09-26'` -> `'26 Sep'`, as the page writes a date. A key that is
+    not a date is shown as it is, because this feeds a status row."""
+    try:
+        d = date.fromisoformat(str(day))
+    except ValueError:
+        return str(day)
+    return f"{d.day} {d:%b}"
 
 
 def _bad_rows(rec) -> int:
@@ -393,9 +405,8 @@ class PriceHistory:
             self.last_error = f"no durable volume at {parent}"
             # INFO, not ERROR: on a dev host or in a test container there is no
             # /data and nothing is wrong.
-            _LOG.info("no price history: %s - §8.3 carry-forward has nothing "
-                      "to carry and the horizon stays as short as the feed",
-                      self.last_error)
+            _LOG.info("No price history is kept (%s), so missing hours are "
+                      "not filled from yesterday's prices.", self.last_error)
             return
         self.ok = True
         self._load()
@@ -437,9 +448,9 @@ class PriceHistory:
             # exactly what this handler says, and a third `ValueError` subclass
             # nobody has thought of is how this defect arrived the first time.
             self.last_error = f"unreadable ({err})"
-            _LOG.warning("price history at %s is %s - starting from empty. "
-                         "§8.3 carry-forward has nothing to carry until the "
-                         "next refresh has written a full day",
+            _LOG.warning("Price history at %s is %s, so it starts empty. "
+                         "Missing hours cannot be filled in until a full day "
+                         "is saved.",
                          self.path, self.last_error)
             return
         found = blob.get("version") if isinstance(blob, dict) else None
@@ -449,15 +460,15 @@ class PriceHistory:
         # would not notice a writer this build has never met.
         if not isinstance(blob, dict) or isinstance(found, bool) \
                 or not isinstance(found, int) or found != SCHEMA:
-            self.last_error = f"schema {found!r}, not {SCHEMA}"
-            _LOG.warning("price history at %s has %s - discarding it rather "
-                         "than guessing what its points mean",
+            self.last_error = f"version {found!r}, not {SCHEMA}"
+            _LOG.warning("Price history at %s has %s, so it is not used.",
                          self.path, self.last_error)
             return
         days = blob.get("days")
         if not isinstance(days, dict):
-            self.last_error = "no `days` object"
-            _LOG.warning("price history at %s has %s", self.path, self.last_error)
+            self.last_error = "no days in it"
+            _LOG.warning("Price history at %s has %s, so it is not used.",
+                         self.path, self.last_error)
             return
         self._days = self._usable_days(days)
 
@@ -504,20 +515,22 @@ class PriceHistory:
             kept[key] = rec
         notes = []
         if dropped:
-            notes.append(f"{len(dropped)} unusable day record(s) dropped "
-                         f"({', '.join(sorted(dropped))})")
+            notes.append(f"{messages.count(len(dropped), 'unusable day')} "
+                         f"dropped, " + ", ".join(day_words(d)
+                                                  for d in sorted(dropped)))
         if malformed:
             notes.append(
-                f"{sum(malformed.values())} malformed point row(s) in "
-                + ", ".join(f"{d} ({n})" for d, n in sorted(malformed.items())))
+                f"{messages.count(sum(malformed.values()), 'bad price')} in "
+                + ", ".join(f"{day_words(d)} ({n})"
+                            for d, n in sorted(malformed.items())))
         if notes:
             # Recorded, not silent: `yesterday()` and `words` both report
             # `last_error`, and a cache that quietly discards half a file reads
             # to an operator exactly like a normal first day.
-            self.last_error = "; ".join(notes)
-            _LOG.warning("price history at %s: %s - the controller starts "
-                         "anyway and the horizon is as short as the feed makes "
-                         "it", self.path, self.last_error)
+            self.last_error = " and ".join(notes)
+            _LOG.warning("Price history at %s: %s. The add-on starts anyway, "
+                         "and fills in only what the rest holds.",
+                         self.path, self.last_error)
         return kept
 
     def _save(self) -> bool:
@@ -680,10 +693,11 @@ class PriceHistory:
             # undone with the rest of the merge, so those rows are still in the
             # file and the next write that completes drops them again.
             self.last_error = (
-                f"{sum(junked.values())} malformed point row(s) dropped from "
-                + ", ".join(f"{d} ({n})" for d, n in sorted(junked.items())))
-            _LOG.warning("price history at %s: %s - the record is rewritten "
-                         "without them and the refresh continues",
+                f"{messages.count(sum(junked.values()), 'bad price')} dropped "
+                f"from " + ", ".join(f"{day_words(d)} ({n})"
+                                     for d, n in sorted(junked.items())))
+            _LOG.warning("Price history at %s: %s. The file is saved without "
+                         "them and the price update goes on.",
                          self.path, self.last_error)
         self._prune(stamp)
         if not self._save():
@@ -752,21 +766,23 @@ class PriceHistory:
         if self.last_error and not self._days:
             return PriceRead.no_data(
                 f"the price history at {self.path} is {self.last_error}, so "
-                f"§8.3 has no profile to carry forward for {want}; the plan "
-                f"covers only the hours the feed published")
+                f"there are no prices from yesterday to fill in for "
+                f"{day_words(want)}. The plan covers only the hours the feed "
+                f"published")
         rec = self._days.get(want)
         if rec is None:
-            have = ", ".join(sorted(self._days)) or "no days at all"
+            have = (", ".join(day_words(d) for d in sorted(self._days))
+                    or "no days at all")
             return PriceRead.no_data(
-                f"no published prices recorded for {want} (held: {have}), so "
-                f"§8.3 has no profile to carry forward. A record for another "
-                f"day is not a yesterday")
+                f"no published prices are kept for {day_words(want)}, only for "
+                f"{have}, so there are no prices from yesterday to fill in. A "
+                f"record for another day is not a yesterday")
         points, bad = _parse_points(rec.get("points"))
         if not points:
             why = bad or "it is empty"
             return PriceRead.no_data(
-                f"the {want} record holds no usable point ({why}), and an "
-                f"empty series is not a free day")
+                f"the {day_words(want)} record holds no usable price, {why}, "
+                f"and an empty series is not a free day")
         try:
             product = PriceProduct(rec.get("product"))
         except ValueError:
@@ -775,8 +791,9 @@ class PriceHistory:
                 f"which is not a PriceProduct. The optimiser switches on that "
                 f"enum, so a record that cannot name one cannot be a series")
         if bad:
-            _LOG.warning("price history: %s in the %s record were dropped; "
-                         "%d point(s) carried forward", bad, want, len(points))
+            _LOG.warning("Price history: %s dropped from the %s record, and "
+                         "%s kept.", bad, day_words(want),
+                         messages.count(len(points), "price"))
         return PriceRead.series(points, product,
                                 str(rec.get("provider") or "price_history"),
                                 stamp)
@@ -805,7 +822,7 @@ class PriceHistory:
         if not self._days:
             why = f" - {self.last_error}" if self.last_error else ""
             return f"empty{why} - nothing to carry forward yet"
-        held = "; ".join(_row_of(d, *_held(self._days[d]))
+        held = ", ".join(_row_of(d, *_held(self._days[d]))
                          for d in sorted(self._days, key=str))
         # A file that PARTLY loaded says so, or the dropped days read as days
         # that were simply never written.
@@ -833,7 +850,7 @@ def _parse_points(raw) -> tuple:
             continue
         out.append(pt)
     out.sort(key=lambda p: p.start.astimezone(timezone.utc))
-    return tuple(out), (f"{dropped} malformed point(s)" if dropped else "")
+    return tuple(out), (messages.count(dropped, "bad price") if dropped else "")
 
 
 class NoHistory:
@@ -861,5 +878,5 @@ class NoHistory:
 
     def yesterday(self, stamp: datetime) -> PriceRead:
         return PriceRead.no_data(
-            "this caller keeps no price history (NoHistory), so §8.3 has no "
-            "profile to carry forward")
+            "this caller keeps no price history, so there are no prices from "
+            "yesterday to fill in")

goodwe_controller/app/pv.py

@@ -0,0 +1,274 @@
+"""TEL-11/TEL-12 - the site's PV production, read from Home Assistant entities.
+
+WHY THIS IS AN ENTITY AND NOT A REGISTER. This add-on's RS485 bus carries the
+BATTERY inverter it drives. A household's PV inverter is, on nearly every site,
+a different box from a different vendor that reports into Home Assistant
+through its own integration - so the only place a product can read production
+for an arbitrary install is an HA entity. `pv_entities` therefore takes whatever
+`sensor.*` the site's own PV integration provides.
+
+⚠️ AND THERE IS USUALLY MORE THAN ONE OF THEM, WHICH IS TEL-12. TEL-11 shipped
+`pv_entity` as a single string and the owner of the reference site reported
+within minutes of 0.11.0 going live that they have SEVERAL PV inverters and
+could configure one. That is not a property of one house: a multi-string or
+multi-orientation roof routinely carries two or three inverters, each
+publishing its own power sensor. `entities()` below is the roster and `total()`
+is the site figure over it.
+
+⚠️ AND A PARTIAL TOTAL IS WORSE THAN NO TOTAL, WHICH IS THE WHOLE OF TEL-12.
+Three inverters configured, one `unavailable`, and the sum of the other two is A
+SMALLER NUMBER INDISTINGUISHABLE FROM A REAL ONE. Fed into OPT-10's attribution
+that reads as "there was less PV than there was" - which is the "no irradiance"
+conclusion the card exists to TEST rather than to manufacture. So `total()`
+answers `None` the moment ANY configured entity is absent. See the note on
+`total()` for the alternative that was weighed and why it lost.
+
+WHY THE CHANNEL EXISTS AT ALL. OPT-10 measured that 20.5 kWh of surplus left the
+site in 16 days while the pack had room, 12.6 kWh of it with the battery not
+charging at all - and could not say WHY, because PV production is recorded
+NOWHERE. Three causes need three different fixes (no irradiance: nothing to fix;
+a charge-power limit; the optimiser declining to charge - the only software
+defect), and guessing between them is how an optimiser gets tuned to solve a
+cloud problem. This module is the missing measurement and NOTHING ELSE.
+
+⚠️ NOTHING HERE MAY EVER REACH A CONTROL DECISION, AND THAT IS THE CARD'S FIRST
+CONSTRAINT RATHER THAN A STYLE NOTE. The add-on regulates a real battery; adding
+production as a term of the control law would be an unrequested behaviour change
+AND it would destroy the measurement, because the loop would then be reacting to
+the quantity being measured. `tools/tel11_pv_trace.py` is what says the path is
+untouched: it grades a control document that contains none of this material on
+both trees and with `pv_entity` set and unset.
+
+⚠️ ABSENCE IS NEVER ZERO, AND THAT IS THE SECOND CONSTRAINT. Every refusal below
+returns `None` with a REASON, never `0.0`. A PV channel that reported 0 W for a
+dead sensor would manufacture exactly the "there was no surplus to store"
+conclusion the card exists to TEST - and it would do it silently, in a week of
+recorder history nobody would re-derive. `app/hass.py`'s own note on `state()`
+is the same rule one layer down. ⚠️ TEL-12 EXTENDS THAT RULE RATHER THAN
+WEAKENING IT: at a roster of three, "one of them is absent" is an absence of the
+SITE figure, and it publishes as an absence. A partial sum is a second way of
+reporting 0-where-there-was-production, one layer up, and it is refused for the
+same reason.
+
+THE SIGN CONVENTION: POSITIVE IS PRODUCTION, as for `meter_entity` and
+`batt_entity` ("power arriving at the house's AC bus"). TEL-14: a kWh meter or
+power clamp in the PV circuit reads the other way, so `pv_invert_entities`
+flips the sign per entity. See `DECISIONS/TEL-14-pv-sign.md`.
+"""
+
+from .hass import BAD_STATES
+
+# Home Assistant's OWN power units, each as the number of watts one of it is.
+# ⚠️ READ OUT OF HA, NOT LISTED FROM MEMORY: `UnitOfPower` in
+# `homeassistant/const.py` (github.com/home-assistant/core, `dev`, retrieved
+# 2026-09-24) declares mW, W, kW, MW, GW, TW and BTU/h. Every factor here is an
+# exact power of ten, so none of them is a number anybody chose.
+#
+# ⚠️ BTU/h IS IN HA's ENUM AND DELIBERATELY NOT HERE. Its factor (0.293071…)
+# is a measured conversion rather than a decimal shift, no PV integration
+# publishes in it, and a wrong constant in the one channel that exists to
+# attribute a 20.5 kWh shortfall is worse than a refusal an operator can read.
+# It lands in the "not a power unit" refusal below, BY NAME.
+WATTS_PER = {
+    "mW": 0.001,
+    "W": 1.0,
+    "kW": 1000.0,
+    "MW": 1000000.0,
+    "GW": 1000000000.0,
+    "TW": 1000000000000.0,
+}
+
+# What `watts()` answers when there is nothing to report. ⚠️ THE REASON IS PART
+# OF THE RETURN VALUE, not a log line: it is what the status page prints, and an
+# absence whose cause is invisible sends an operator to look at the wrong box.
+UNIT_KEY = "unit_of_measurement"
+
+
+def watts(state: dict | None) -> tuple:
+    """`(watts, why)` from a Home Assistant state object.
+
+    `watts` is `None` whenever there is no reading - and `why` then says which
+    of the five refusals it was, in words an operator can act on. On a good read
+    `why` is the unit the value was read in, because "1234 W" and "1234, unit
+    unknown" are different claims and the page has to be able to make the first.
+
+    ⚠️ THE UNIT IS READ OFF THE ENTITY AND NOT ASSUMED, AND THERE IS NO
+    MAGNITUDE HEURISTIC. `read_inputs()` guesses kW-or-W for
+    `peak_forecast_entity` with `abs(raw) < 50`, which is safe there because
+    nobody's quarter-hour demand forecast is 50 W. It is NOT safe here: 30 W of
+    real production at dusk is an ordinary reading, and that heuristic would
+    publish it as 30 kW - a fabricated number, in the channel whose entire
+    purpose is to be believed a week later. A sensor whose unit this cannot read
+    is REFUSED rather than guessed at.
+    """
+    if state is None:
+        # `hass.state()` answers None for a non-existent entity, a 404 and a
+        # transport failure alike. All three are "no reading", and HA does not
+        # consider a non-existent entity an error - see `hass.state()`.
+        return None, "no state (entity missing, or the read failed)"
+    raw = str(state.get("state", "")).strip()
+    if raw.lower() in BAD_STATES:
+        # ⚠️ THE SAME LIST `hass.number()` REFUSES ON, IMPORTED RATHER THAN
+        # RESPELLED. A second copy of it is how one path starts treating
+        # `unavailable` as a number the other one rejects.
+        return None, f"entity is {raw or 'empty'}"
+    try:
+        value = float(raw)
+    except ValueError:
+        return None, f"state {raw!r} is not numeric"
+    unit = str((state.get("attributes") or {}).get(UNIT_KEY) or "").strip()
+    if not unit:
+        return None, ("no unit_of_measurement on the entity - it cannot be "
+                      "read in watts")
+    if unit not in WATTS_PER:
+        return None, (f"unit {unit!r} is not one of "
+                      f"{', '.join(WATTS_PER)} - it cannot be read in watts")
+    return value * WATTS_PER[unit], unit
+
+
+# --- TEL-12: the ROSTER, and the SITE figure over it --------------------------
+
+def entities(opts: dict) -> tuple:
+    """Every PV entity this configuration names, in configured order. TEL-12.
+
+    ⚠️ ONE ANSWER TO "WHICH ENTITIES ARE THE PV CHANNEL", and it is the answer
+    BOTH sides read. `Controller.pv_roster` is this call and
+    `mqtt.optional_keys()` is `bool()` of this call, so the thing that decides
+    whether the row is ANNOUNCED, the thing that decides whether it is READ and
+    the thing that decides HOW MANY entities are summed cannot disagree. TEL-11
+    already had that discipline for one entity and spelled the predicate TWICE
+    - `str(opts.get("pv_entity") or "").strip()` in `main.py` and again in
+    `mqtt.py`. Two spellings of one predicate is how an entity gets announced
+    that nothing feeds; a roster makes it how a SUM gets taken over a different
+    list from the one that was announced. It is one function now.
+
+    ⚠️ `pv_entities` REPLACES `pv_entity` RATHER THAN EXTENDING IT, and that is
+    CFG-04's shipped precedent (`inverters:` replaces the six flat keys) applied
+    to the only upgrade path that matters. The install this card exists for HAS
+    `pv_entity` set, to inverter A. Opening the Configuration tab, the natural
+    action is to put ALL the inverters in the new repeatable field - and under a
+    UNION rule that double-counts A unless the operator also remembers to clear
+    the old key. A doubled total is the same defect as a partial one in the
+    other direction, in the one channel that exists to be believed a week later.
+    Under REPLACE the effective roster is exactly what one key says, and no
+    arithmetic depends on a de-duplication rule the operator has to know about.
+    ⚠️ `Controller.checks()` says WHICH key is in use whenever both are set, so
+    the replacement is stated on the page rather than being silent.
+
+    ⚠️ AND IT DE-DUPLICATES WITHIN THE LIST, ORDER PRESERVED. A site cannot have
+    two sensors with one entity_id, so a repeated id in the list is never a
+    second inverter - it is a typo that would DOUBLE that inverter's production
+    in the total. `dict.fromkeys` is the order-preserving spelling.
+    """
+    listed = [e for e in (str(x or "").strip()
+                          for x in (opts.get("pv_entities") or [])) if e]
+    if listed:
+        return tuple(dict.fromkeys(listed))
+    one = str(opts.get("pv_entity") or "").strip()
+    return (one,) if one else ()
+
+
+def entity_is_ignored(opts: dict) -> bool:
+    """Is a set `pv_entity` being REPLACED by a set `pv_entities`? TEL-12.
+
+    ⚠️ HERE RATHER THAN IN `Controller.checks()`, for the reason `entities()`
+    exists: the rule and the sentence that reports the rule must not be two
+    readings of the options. This is the negative half of `entities()`' first
+    branch and it is spelled once, beside it, where an edit to one is in front
+    of whoever is editing the other.
+    """
+    return bool(str(opts.get("pv_entity") or "").strip()
+                and [x for x in (opts.get("pv_entities") or [])
+                     if str(x or "").strip()])
+
+
+def inverted(opts: dict) -> frozenset:
+    """The entity ids `pv_invert_entities` flips. TEL-14."""
+    return frozenset(e for e in (str(x or "").strip()
+                                 for x in (opts.get("pv_invert_entities") or []))
+                     if e)
+
+
+def stray_inverts(opts: dict) -> list:
+    """`pv_invert_entities` entries naming no entity in the roster - a typo
+    that would otherwise leave a sign unflipped with nothing said. TEL-14."""
+    roster = set(entities(opts))
+    return sorted(e for e in inverted(opts) if e not in roster)
+
+
+# TEL-14: a reading below this is not standby draw. A correctly signed meter in
+# the PV circuit reads a few watts NEGATIVE at night (the owner's: 13 W); -50 W
+# clears that with room for a couple of such devices on one entity, while a
+# reversed sensor in daylight reads hundreds to thousands of watts below zero.
+NEGATIVE_W = -50.0
+
+
+def total(readings, flip=frozenset()) -> tuple:
+    """`(watts, why, parts)` - the SITE's production, or an ABSENCE. TEL-12.
+
+    `readings` is `[(entity_id, state), ...]` in `entities()` order, one entry
+    per configured entity, each `state` shaped as `hass.state()` returns.
+
+    `parts` is `[(entity_id, watts, why), ...]` - EVERY entity's own answer from
+    `watts()`, kept because the operator surfaces have to be able to name which
+    sensor is missing. `watts` is the sum when every entity answered, and `None`
+    otherwise; `why` always says which of those it was, in words a status page
+    can print.
+
+    ⚠️ ONE OR MORE ABSENT -> THE TOTAL IS ABSENT. NOT THE PARTIAL SUM. This is
+    the decision the card turns on and it was taken deliberately against the
+    alternative, which was to publish the partial sum ALONGSIDE a count of how
+    many entities contributed. Both are defensible; this one wins on the ONE
+    question that matters, which is who reads the number and when:
+
+      * the MQTT row is read back COLD, a week later, by OPT-10's attribution
+        and by whatever plots `sensor.goodwe_pv_power` over that week. A partial
+        sum there is a smaller number indistinguishable from a real one, and the
+        count that would have qualified it lives in a SECOND entity with its own
+        history - so believing the total requires joining two recorder series by
+        timestamp to find out which samples to distrust. Nobody re-derives that,
+        which is the same "nobody will re-derive it" TEL-11's note names. And it
+        is worse than a gap in exactly the direction that matters: a gap makes
+        the attribution say "I do not know", a partial sum makes it say "there
+        was less sun than there was".
+      * the STATUS PAGE is read LIVE, by a human, who wants the diagnostic. So
+        the partial information is not thrown away - `Controller.checks()` names
+        every entity that DID report, with its watts, and every one that did
+        not, with its reason, in a row that states plainly that there is no site
+        total. Different reader, different instant, different rule.
+
+    A count published beside the total would also carry no information in the
+    state this function actually admits: the total is published ONLY when every
+    entity contributed, so the count would be the constant `len(parts)`.
+
+    ⚠️ AND `0 W` IS STILL A READING AT EVERY ROSTER SIZE - the test is
+    `watts is None`, never falsiness. An inverter honestly reporting 0 W at dusk
+    beside two that are producing must give the SUM of the three, not blank the
+    site: shading, a tripped string and nightfall are all real 0s, and a roster
+    that went to `unknown` whenever one member read zero would report an absence
+    on every clear evening and defeat the channel from the other end.
+
+    ⚠️ TEL-14: `flip` is `inverted(opts)`; each member's sign is applied HERE,
+    before the sum, so every surface reads the corrected figure. `0.0 - w`
+    rather than `-w`, so a flipped 0 W is `0.0` and never `-0.0` on the wire.
+    """
+    parts = [(ent, w if w is None or ent not in flip else 0.0 - w, why)
+             for ent, (w, why) in ((e, watts(st)) for e, st in readings)]
+    if not parts:
+        # No roster. `Controller` does not call this in that state - the gate is
+        # `pv_roster` - but a reader of `parts` should never have to wonder.
+        return None, "not configured", parts
+    if len(parts) == 1:
+        # ⚠️ AT ONE ENTITY THIS IS `watts()` AND NOTHING ELSE: the same value
+        # and the SAME `why` string, passed through rather than re-composed, so
+        # 0.11.0's single-entity surfaces are byte-identical rather than
+        # similar. `tools/tel11_pv_trace.py` grades that identity across trees.
+        return parts[0][1], parts[0][2], parts
+    missing = [(ent, why) for ent, w, why in parts if w is None]
+    if missing:
+        return None, (
+            f"only {len(parts) - len(missing)} of {len(parts)} entities are "
+            f"reporting and a partial sum would understate production: "
+            + "; ".join(f"{ent} - {why}" for ent, why in missing)), parts
+    return (sum(w for _e, w, _y in parts),
+            f"{len(parts)} entities", parts)

goodwe_controller/app/selfconfig.py

@@ -82,6 +82,7 @@ import os
 
 import aiohttp
 
+from . import messages
 from .configui import changed_keys
 from .inverter import build_roster
 from .validate import validate_startup_config, validate_unit_ranges
@@ -130,11 +131,16 @@ class SaveRefused(Exception):
     own sentences, byte for byte; `changed` names the keys that moved.
     """
 
-    def __init__(self, kind, problems=(), changed=(), stored=None):
+    def __init__(self, kind, problems=(), changed=(), stored=None,
+                 moved=None):
         self.kind = kind
         self.problems = list(problems)
         self.changed = list(changed)
         self.stored = stored
+        # UX-13 P4: the keys the OTHER surface changed - stored-on-open
+        # against stored-now - when the caller knows what it opened. None
+        # when it does not. `changed` also holds the operator's own edits.
+        self.moved = None if moved is None else list(moved)
         super().__init__(f"save refused ({kind})")
 
 
@@ -287,7 +293,7 @@ async def problems_for(opts: dict, hass=None) -> list:
     return problems
 
 
-async def problems_and_ranges(opts: dict, hass=None):
+async def problems_and_ranges(opts: dict, hass=None, notes=None):
     """`problems_for()`, plus WHICH setpoint entities did not report a range.
 
     ⚠️ THE SECOND HALF EXISTS SO THE PAGE CANNOT LOOK GREEN FOR A REASON THE
@@ -302,6 +308,8 @@ async def problems_and_ranges(opts: dict, hass=None):
     has just typed a new `setpoint_entity` must be told about THAT entity, and
     a route that asked the running controller instead would report on the old
     one. That was the first shape of this and it disagreed with itself.
+
+    UX-13: a list passed as `notes` collects the validator's warnings too.
     """
     flat = str(opts.get("setpoint_entity", "") or "").strip()
 
@@ -328,7 +336,7 @@ async def problems_and_ranges(opts: dict, hass=None):
         # disagreement is itself the finding - so it is reported rather than
         # swallowed. Returning `[]` here would turn a crash into a silent
         # acceptance, which is worse than the 500 this replaced.
-        found = list(validate_startup_config(opts))
+        found = list(validate_startup_config(opts, notes=notes))
         if not found:
             found = [f"the configuration could not be composed ({type(exc).__name__}: "
                      f"{exc}), and the validator did not name a reason. This is a "
@@ -346,7 +354,8 @@ async def problems_and_ranges(opts: dict, hass=None):
         if flat and unit.setpoint_entity.strip().lower() == flat.lower():
             dev_min, dev_max = unit.dev_min, unit.dev_max
             break
-    problems = list(validate_startup_config(opts, dev_min, dev_max))
+    problems = list(validate_startup_config(opts, dev_min, dev_max,
+                                            notes=notes))
     problems += validate_unit_ranges(units, skip_entity=flat)
     unread = [unit.setpoint_entity for unit in units
               if unit.setpoint_entity and unit.dev_min is None
@@ -355,7 +364,7 @@ async def problems_and_ranges(opts: dict, hass=None):
 
 
 async def save(selfcfg: SelfConfig, proposed: dict, expect: str, *,
-               hass=None) -> dict:
+               hass=None, base=None) -> dict:
     """Validate, compare-and-swap, then write. Refuse rather than half-do.
 
     Returns `{"fingerprint": <the new one>}` on success. Raises `SaveRefused`
@@ -378,11 +387,17 @@ async def save(selfcfg: SelfConfig, proposed: dict, expect: str, *,
     genuinely wants what the other surface wrote replaced, the page reloads,
     shows them what changed, and they save again from THAT - which is a
     decision made in front of the difference rather than through it.
+
+    `base`, when given, is the blob the page opened (the one `expect` is the
+    fingerprint of). A stale refusal then also names the keys that moved
+    underneath it, so the page does not list the operator's own edits among
+    the settings "changed elsewhere" (UX-13 P2 test, finding a).
     """
     problems = await problems_for(proposed, hass)
     if problems:
-        _LOG.warning("panel REFUSED to save: %d configuration problem(s); "
-                     "nothing written. First: %s", len(problems), problems[0])
+        _LOG.warning("The settings page did not save, because of %s. The "
+                     "first: %s", messages.count(len(problems), "problem"),
+                     problems[0])
         raise SaveRefused("invalid", problems=problems)
 
     info = await selfcfg.info()
@@ -390,10 +405,15 @@ async def save(selfcfg: SelfConfig, proposed: dict, expect: str, *,
     actual = fingerprint(stored)
     if actual != expect:
         changed = changed_keys(stored, proposed)
-        _LOG.warning("panel REFUSED to save: the stored options changed "
-                     "underneath this page (keys: %s); nothing written",
-                     ", ".join(changed) or "none this page also edited")
-        raise SaveRefused("stale", changed=changed, stored=stored)
+        moved = (changed_keys(base, stored)
+                 if isinstance(base, dict) and fingerprint(base) == expect
+                 else None)
+        keys = changed if moved is None else moved
+        _LOG.warning("The settings page did not save, because the settings "
+                     "changed while it was open (keys: %s).",
+                     ", ".join(keys) or "none this page also edited")
+        raise SaveRefused("stale", changed=changed, stored=stored,
+                          moved=moved)
 
     await selfcfg.write_options(proposed)
     _LOG.info("options saved from the ingress panel; a restart is needed "

goodwe_controller/app/shadow.py

@@ -0,0 +1,506 @@
+"""SAFETY-10 - shadow mode: the whole decision path, and no command.
+
+WHAT DEFECT THIS PREVENTS
+=========================
+Not one defect - the CLASS of them. Every optimiser fault this repository has
+found was invisible from outside while it was happening, and each one was paid
+for at the meter before anybody could see it:
+
+  * SAFETY-45  arbitrage against a binding `peak_cap_w` ran 28 charge onsets an
+               hour, the grid swinging -455 .. +3200 W, and put a billed
+               quarter 59 W over the cap;
+  * TARIFF-14  the price lookup answered for the wrong quarter-hour 45 minutes
+               in every 60, and traded on it;
+  * SAFETY-46  the SoC ceiling churns 598 Wh to gain 310 Wh, no hysteresis.
+
+There was no way to WATCH what the optimiser would do without letting it do it.
+A commissioning engineer could arm arbitrage and find out, or not arm it and
+learn nothing. Shadow mode is the third option: strategies, arbiter, clamps and
+guards all run, the decision is recorded with its reason, and NOTHING THE
+CONTROLLER DECIDES REACHES THE INVERTER.
+
+⚠️ AND OF THOSE THREE, A SHADOW RUN CAN SHOW YOU EXACTLY ONE - SEE THE NEXT
+   SECTION. This header used to name SAFETY-45's limit cycle as the example
+   of what shadow mode surfaces. That was false, and SAFETY-47 measured it.
+
+⚠️ WHAT A SHADOW RUN CAN AND CANNOT SHOW  (SAFETY-47)
+=====================================================
+SHADOW MODE CANNOT SURFACE A CLOSED-LOOP DEFECT. Not badly, not partially -
+NOT AT ALL, and by the same construction that makes it safe. The actuator is
+held at WIRE_W and the carried command is re-seeded to WIRE_W, so every
+MEASURED input - the meter, the quarter accumulator behind it, the battery
+power, the state of charge - describes a plant that DID NOT RESPOND. A
+closed-loop defect is by definition one whose stimulus is the plant's response
+to the controller. No response, no stimulus, no defect to see.
+
+That is not a gap to be closed later. Feeding the guards a simulated plant
+instead is what SAFETY-10 §4 refuses for the sign watchdogs, for a reason that
+applies to all of this: a controller reacting to a plant that does not exist
+drifts further from reality every tick, and three cycles in its numbers
+describe nothing. THE CLOSED-LOOP ANSWER COMES FROM A CLOSED-LOOP RIG
+(TEST-23 stage 3) OR FROM A LIVE RUN. There is no third place.
+
+So, of the three defects above, measured on that rig at `peak_cap_w` 1500 /
+house 1200 / `max_w` 2000, one hour at a 5 s cycle:
+
+  * SAFETY-45's limit cycle    NOT VISIBLE. Live: 28 charge onsets, the grid
+                               swinging -455.5 .. +3200.0 W, the guard engaged
+                               on 410 of 720 cycles. Shadow, same hour, same
+                               code: 1 onset, the grid flat at the 1200 W
+                               house, the guard engaged on 0 of 720. Every
+                               term of `wanted = batt_w + excess` is measured.
+  * SAFETY-46's SoC churn      NOT VISIBLE. The SoC moves 0.000000000 pp in a
+                               shadow run, because it is the pack's integral of
+                               what the pack was commanded and the pack was
+                               commanded 0 W. No SoC limit can be REACHED in a
+                               shadow run; the ones already crossed when it
+                               started are reported, and that is all.
+  * TARIFF-14's wrong quarter  VISIBLE, and it is the one. The price lookup's
+                               inputs are the CLOCK and the PRICE SERIES, and
+                               neither is a function of what the battery did.
+                               Measured: which hour the strategy picked, its
+                               price and the spread it cleared are identical
+                               live and shadow on 720 of 720 charging cycles,
+                               AT A BINDING CAP.
+
+⚠️ THE EXEMPTION THAT USED TO BE HERE WAS TRUE UNTIL SAFETY-45 MERGED. This
+module, DOCS.md and DECISIONS/SAFETY-10-shadow-mode.md all said "the strategies
+are unaffected - they ask for a fixed power from inputs that do not depend on
+what the battery did". SAFETY-45 made the buy leg `min(asked, headroom)` with
+
+    headroom = (900 / remaining) x (ceiling - projected)
+
+and `projected` reads the OPEN QUARTER'S ACCUMULATOR - the meter - which is a
+function of what the battery did earlier in that same quarter. The strategy
+became closed-loop the day that landed. What survives of the exemption, and
+only this:
+
+    WHICH hour a strategy picks, and WHY, are unaffected.
+    HOW HARD it trades is not.
+
+⚠️ AND THE SIZE A SHADOW RUN RECORDS IS THE RIGHT ANSWER TO A QUESTION NOBODY
+   ASKED. `900/remaining` is correct arithmetic for a meter that is genuinely
+under the ceiling - and in shadow the meter genuinely IS under it, because the
+battery is not charging. So the number is not a bug; it is an answer computed
+for a plant that did not exist. Measured on the same rig, shipped code:
+
+    cap / house      live commanded      shadow recorded      over
+    1500 / 1200         -302.4 W            -2000.0 W         6.61x
+    3500 / 3000         -502.6 W            -2000.0 W         3.98x
+    3500 / 2000        -1502.6 W            -2000.0 W         1.33x
+    3500 / 1800        -1702.6 W            -2000.0 W         1.17x
+   15000 /  350        -2000.0 W            -2000.0 W         1.00x
+
+The last row is the fixture SAFETY-10's own evidence was taken on, which is why
+nothing reported this. `words()` carries the caveat rather than a re-computed
+number, and `DECISIONS/SAFETY-47-what-a-shadow-run-can-show.md` §3 records the
+three alternatives that were rejected and why.
+
+⚠️ "REACHES NOTHING" IS NOT "WRITES NOTHING", AND THE DIFFERENCE IS THE WHOLE
+   SAFETY ARGUMENT
+=======================================================================
+The inverter holds its last command FOREVER - it has no meter timeout
+(HANDOVER.md §6), and firmware/goodwe-master.yaml's header records what that
+cost when a controller stopped refreshing: Illusmart went silent mid-command
+and the inverter held +5000 W for 113 s. main.py's own header carries the same
+measurement. So a shadow mode that
+simply stopped writing would leave whatever was standing when it was switched
+on standing for as long as it was left on. That is the exact failure this
+repository keeps finding - LOOKS HEALTHY BUT IS INERT - with the status page
+calmly reporting that nothing is being commanded.
+
+So shadow mode does write, and it writes ONE number:
+
+    the actuator is held at WIRE_W (0.0 W), refreshed on the ordinary
+    heartbeat, by the ordinary single writer.
+
+That is a DEFINED, SAFE actuator state, it is the same state the operator's
+stop button reaches, and it honours the contract firmware/goodwe-master.yaml
+§"CONTRACT CHANGE" imposes on us - HA must rewrite the setpoint every ~10 s or
+the ESP32's 30 s stale-input watchdog cannot tell "steady" from "dead". Going
+silent would put that board into a tripped-watchdog state for the whole shadow
+run, which is an ALARM being used as a MODE: the operator who learns that
+`wd_tripped` is normal during shadow runs is the operator who ignores it when
+the add-on has actually died.
+
+⚠️ AND IT IS NOT A SECOND WRITE PATH. SAFETY-28's rule is one actuator, one
+writer. Shadow mode files no claim, owns no transport and calls nothing in
+hass.py. It is a SUBSTITUTION inside `Controller._write_unit()` - the single
+choke point every write in this add-on already goes through - in exactly the
+form the three substitutions above it take (non-finite -> 0 W, unauthorised ->
+0 W, clamped -> the rating). It is the LAST of them, so SAFETY-28's
+authorisation gate and SAFETY-03's clamp still grade the number the decision
+path actually produced, and a shadow run therefore records that the clamp WOULD
+have engaged.
+
+THE DEFAULT, AND WHY IT IS NOT A PLAIN `true`  (§ the ticket's own warning)
+==========================================================================
+The card is titled "default-on". Taken literally - `shadow_mode: true` in
+`config.yaml`'s `options:` block - it is the worst change in this repository's
+history. Home Assistant's Supervisor composes an add-on's effective options as
+`{**config.yaml defaults, **the stored user options}`, so a NEW key with a new
+default reaches EVERY install on the next update, including the one regulating
+a real battery in the author's house today. Literal default-on silently stops
+an existing install from controlling, and the only symptom is a battery that
+has stopped doing anything.
+
+There is no mechanism in the add-on options system that lets one key default
+differently for a new install and an existing one: `options:` IS the default,
+and there is exactly one of it. So "default-on for new" has to be expressed as
+a value the add-on RESOLVES, not as a constant the Supervisor merges.
+
+Hence three values rather than two, defaulting to `auto`:
+
+    off    never shadow. The controller commands the battery.
+    on     always shadow, whatever the start/stop button says.
+    auto   shadow WHILE CONTROL IS STOPPED; live once it is started.
+
+`auto` is default-on for a new install and a no-op for an existing one, and it
+is that without any persisted marker, any migration, and any guess:
+
+  * a FRESH install ships `auto_start: false` and has no stored `auto` key, so
+    it comes up stopped -> shadow. It observes a day of decisions before it is
+    ever allowed to command anything. That is the card's intent, delivered.
+  * an install that is CONTROLLING - `auto_start: true`, or the operator has
+    pressed *Start / stop control* and the store carries `auto: true` - is
+    started, so `auto` resolves to LIVE and its behaviour does not change by
+    one watt.
+  * an install that is STOPPED keeps its actuator at 0 W exactly as before -
+    the same number, from the same writer, on the same heartbeat - and gains
+    the recording. The only thing that changes for it is what the status page
+    and the action log SAY.
+
+⚠️ AND `auto` MEANS THE START BUTTON LEAVES SHADOW MODE. That is deliberate:
+under `auto` the button reads "Start / stop control" and pressing Start is the
+operator saying "control the battery". An operator who wants the decisions
+recorded WHILE the loop runs sets `shadow_mode: on` explicitly - that is the
+configuration this card exists to make possible, and it is the one that cannot
+be reached by accident.
+
+⚠️ AN UNRECOGNISED VALUE RESOLVES TO SHADOW, NOT TO LIVE. `validate.py` refuses
+it at startup so this is not meant to be reachable, but the fail-safe direction
+for "the operator's intent is unreadable" is the one that does not move energy.
+
+THE FAILSAFES, ONE BY ONE (the card asks for each to be decided and recorded)
+============================================================================
+| failsafe                       | in shadow mode                            |
+|--------------------------------|-------------------------------------------|
+| SAFETY-02/30 sign watchdogs    | INERT, and by construction rather than by |
+| (per-unit and site)            | a special case. They grade                |
+|                                | `Inverter.standing_w()` - what this       |
+|                                | controller has standing on the wire - and |
+|                                | shadow mode holds that at 0 W. A 0 W      |
+|                                | command cannot oppose a meter, so the     |
+|                                | detector never arms. ⚠️ THIS IS THE ONE   |
+|                                | THAT HAD TO BE GOT RIGHT: fed the SHADOW  |
+|                                | decision instead, every shadow run would  |
+|                                | latch a trip within `sign_disagree_s` -   |
+|                                | the decision opposes a meter that never   |
+|                                | saw it - and that latch SURVIVES INTO     |
+|                                | LIVE OPERATION and a restart. Shadow mode |
+|                                | would manufacture the failsafe it is      |
+|                                | meant to help debug.                      |
+| SAFETY-03 clamp                | OBSERVES. It runs on the number the       |
+|                                | decision path produced, `clamp_last` is   |
+|                                | set and every engagement goes to the      |
+|                                | action log, because "it would have hit    |
+|                                | the rating" is part of what a shadow run  |
+|                                | is for. It changes no command: the value  |
+|                                | it narrows is replaced by 0 W below it.   |
+| SAFETY-28 write authorisation  | OBSERVES, for the same reason and in the  |
+|                                | same place - above the substitution, so   |
+|                                | it still asks who chose the number.       |
+| SAFETY-18 meter freeze         | OBSERVES, unchanged. It takes no action   |
+|                                | in live operation either; it grades the   |
+|                                | resolved intent against a meter that has  |
+|                                | stopped moving, and both halves are as    |
+|                                | true in shadow as out of it.              |
+| SAFETY-07/24/25 peak guard     | OBSERVES, AND SEES ONLY THE HOUSE. It is  |
+|                                | level-triggered and unlatched and it files|
+|                                | its claim as usual, so the recorded       |
+|                                | decision is the real one FOR THIS METER - |
+|                                | but every term of `wanted = batt_w +      |
+|                                | excess` is measured, and in shadow mode   |
+|                                | the battery contributes nothing to either.|
+|                                | ⚠️ SAFETY-47: this row used to claim      |
+|                                | SAFETY-45's limit cycle was visible from a|
+|                                | shadow run. It is not - 410/720 engaged   |
+|                                | cycles live against 0/720 in shadow, on   |
+|                                | the same hour and the same code.          |
+| SAFETY-31 circulation          | OBSERVES AND MAY LATCH, legitimately. Its |
+| SAFETY-42 delivery             | evidence is MEASURED power, not a         |
+|                                | command: packs pushing against each other |
+|                                | while every one of them is told 0 W is a  |
+|                                | real fault and a latch is the right       |
+|                                | answer to it.                             |
+| operator stop (`auto` False)   | SUPPRESSED AS A CLAIM, ENFORCED AT THE    |
+|                                | WIRE. It is the one deliberate change.    |
+|                                | Its `P_SAFETY` 0 W claim out-ranks        |
+|                                | everything, so leaving it in would make   |
+|                                | the recorded decision "stopped" on every  |
+|                                | cycle - the shadow run would answer the   |
+|                                | wrong question. The actuator state is     |
+|                                | identical either way, and the wire        |
+|                                | substitution is STRICTLY STRONGER than    |
+|                                | the claim: a claim can be out-ranked, and |
+|                                | this cannot.                              |
+| inputs missing, non-finite,    | UNCHANGED. All of them resolve to 0 W,    |
+| allocator refusal, arbiter     | which is what the wire gets in shadow     |
+| contradiction                  | mode anyway, so they act redundantly and  |
+|                                | are recorded as they always were.         |
+
+⚠️ MAINTENANCE IS NOT IN THAT TABLE BECAUSE SHADOW MODE DOES NOT TOUCH IT. The
+state machines are ticked on every cycle today whether control is started or
+not, so a stopped install already runs them against a battery that does not
+move. Shadow mode inherits that, unchanged and unimproved; it is a pre-existing
+property of `auto_start: false` and it is recorded here rather than quietly
+fixed under another card's name.
+
+LEAVING SHADOW MODE
+===================
+`Controller.cycle()` re-seeds its carried command (`self.target` and each
+`inv.target`) to WIRE_W at the END of every shadow cycle, AFTER every in-cycle
+guard has read the decision. Two things follow, and both are safety properties:
+
+  * the loop's `prev_w` and its integrator track WHAT IS ACTUALLY STANDING ON
+    THE WIRE, so every shadow cycle answers "from where the plant really is,
+    what would this controller do NOW" - a true statement about the present,
+    rather than a simulation of a counterfactual plant that drifts further from
+    reality every tick;
+  * the exit is safe BY CONSTRUCTION. The carried command already equals the
+    standing command, so the first live cycle slews from 0 W like any other
+    cycle. Carrying the shadow decision instead would let the slew limiter
+    depart from a base that never existed - up to a full `slew_w` step onto a
+    battery sitting at zero.
+
+The entry is safe for the ordinary reason: the substitution happens on the very
+first write of the very first shadow cycle, and `last_write` was not 0 W, so
+that write is issued rather than skipped as unchanged.
+"""
+from __future__ import annotations
+
+from . import messages
+
+# ⚠️ CFG-03's mirror. `test_defaults_pin.py` part 2 discovers every
+# module-level name ending in OPTION_DEFAULTS and asserts each value
+# reproduces config.yaml EXACTLY, so this table cannot drift from the shipped
+# default. Nothing in the add-on may carry a literal fallback for a key a
+# mirror answers for - part 3 scans for that - which is why `main.py` asks the
+# functions below and never reads `shadow_mode` itself.
+SHADOW_OPTION_DEFAULTS = {
+    "shadow_mode": "auto",
+}
+
+#: The three values `shadow_mode` may take, in the order config.yaml's schema
+#: lists them. `validate.py` refuses anything else by name.
+MODES = ("auto", "on", "off")
+
+#: What stands on the wire while shadow mode is engaged. ⚠️ A NUMBER, NOT A
+#: SILENCE - see this module's header. It is 0.0 W for the same reason every
+#: other refusal in this add-on is 0.0 W: fail toward inaction, and keep
+#: commanding it so the inverter cannot be left latched on anything else.
+WIRE_W = 0.0
+
+#: SAFETY-47. What the recorded watts mean when a MEASURED billed quarter sized
+#: them.
+#:
+#: ⚠️ "UPPER BOUND" AND NOT "SMALLER", AND THE DIFFERENCE WAS MEASURED RATHER
+#: THAN ARGUED. Charging only ADDS offtake, so a live meter's `projected` is
+#: never below a shadow meter's and the headroom is never above it: the shadow
+#: size is >= the live size, with EQUALITY at the start of every quarter, where
+#: `900/remaining` is 1.0 and neither plant has moved. Measured pairwise over
+#: 3600 charging cycles in five configurations - 0 cycles below, 730 exactly
+#: equal. A sentence reading "smaller" would have been false on every one of
+#: those 730.
+#:
+#: ⚠️ AND IT NAMES NO FACTOR. How far under the bound a live run lands is a
+#: property of the site - 6.61x at a 1500 W cap under a 1200 W house, 1.00x at
+#: a cap that does not bind - and a number invented for the row would be a
+#: second helping of the defect this constant exists to disclose.
+SIZED_FROM_METER = (
+    "This is an upper limit, not a forecast, because the meter did not see "
+    "the battery move.")
+
+
+def mode(opts: dict) -> str:
+    """The configured `shadow_mode`, normalised to one of `MODES`.
+
+    ⚠️ AN UNRECOGNISED VALUE ANSWERS `"on"`, NOT `"auto"` AND NOT `"off"`.
+    `validate.py` refuses such a value at startup, so this branch is not meant
+    to be reachable at all; it exists because the fail-safe direction for "the
+    operator's intent cannot be read" is the one that does not move energy. A
+    typo that silently resolved to `off` would put a battery under a controller
+    whose configuration nobody could parse.
+    """
+    raw = opts.get("shadow_mode", SHADOW_OPTION_DEFAULTS["shadow_mode"])
+    text = str("" if raw is None else raw).strip().lower()
+    if text in MODES:
+        return text
+    return "on"
+
+
+def engaged(opts: dict, *, control_started: bool) -> bool:
+    """Is the battery being left alone right now?
+
+    `control_started` is `Controller.auto` - the persisted start/stop state,
+    which a fresh install gets from `auto_start` and an operator moves with the
+    *Start / stop control* button. See the header on why `auto` reads it.
+    """
+    m = mode(opts)
+    if m == "off":
+        return False
+    if m == "on":
+        return True
+    return not control_started
+
+
+def why(opts: dict, *, control_started: bool) -> str:
+    """Which rung decided, in the words an operator can act on.
+
+    ⚠️ THE REASON, NOT ONLY THE VERDICT - MUTATION.md's masking rule. `on` and
+    `auto`-while-stopped produce the same boolean and want different operator
+    actions: one is turned off by editing an option, the other by pressing a
+    button. A surface that showed only "shadow" would make a mutation that
+    swapped the two rungs invisible.
+    """
+    # ⚠️ THE LIVE SENTENCES SAY "NOT IN SHADOW MODE", NOT "THE BATTERY IS
+    # BEING CONTROLLED". The second is FALSE on a stopped install with
+    # `shadow_mode: off` - nothing is regulating there either - and a row that
+    # is false in one of the four live states is a row an operator learns to
+    # discount. What is true in every live state is that what this add-on
+    # decides reaches the inverter; whether control is RUNNING is the
+    # `Stopped` banner's question and it is answered there.
+    # UX-08: the same four rungs, in plain words. The setting is named by its
+    # value, "automatic" for `auto`, so each rung still reads differently.
+    m = mode(opts)
+    live = "what the add-on decides reaches the inverters"
+    inert = "the add-on decides but sends nothing"
+    if m == "off":
+        return f"Off, {live}"
+    if m == "on":
+        return f"On, {inert}"
+    if control_started:
+        return f"Off (automatic, control is started), {live}"
+    return f"On (automatic, control is stopped), {inert}"
+
+
+def words(opts: dict, *, control_started: bool, would_w: float | None,
+          sized_from_meter: bool, reason: str = "") -> str:
+    """The status page's `Shadow mode` row.
+
+    ⚠️ THE ROW IS RENDERED IN EVERY STATE, INCLUDING `off`. A surface whose
+    ABSENCE is how you learn which mode you are in is a surface an operator
+    has to already know about; TARIFF-11's rule is that the rendered text is
+    what gets graded, so there has to be text in both states.
+
+    `would_w` is the decision the path reached this cycle - what a live
+    controller would have put on the wire GIVEN THIS METER AND A BATTERY AT
+    0 W - and `reason` is `Resolution.explain()`, the same sentence the `Why`
+    row carries. Together they are the whole of "what would it have done, and
+    why"; without them the row would say a shadow run happened and nothing
+    about what it found.
+
+    ⚠️ `sized_from_meter` HAS NO DEFAULT, AND THAT IS SAFETY-47's WHOLE POINT.
+    It is True when a MEASURED billed-quarter headroom sized the number being
+    recorded - `arbitrage.sized_from_meter()` answers it, and it is the one
+    place the question is asked. A default of False here would be a caller
+    that forgot the caveat rendering a row that reads exactly like a caller
+    that decided it did not apply, which is the shape of defect this card is
+    about. TEST-14's rule with a new name on it.
+
+    ⚠️ AND THE PHRASE IS "THIS CYCLE", UNCONDITIONALLY, NOT ONLY WHEN THE
+    CAVEAT FIRES. Every number a shadow run records was reached from a plant
+    that did not respond; "would ask for -2 000 W" alone reads as a forecast
+    of a live run and no number here is one. UX-08 2d put it in plain words. The ⚠️ below is the STRONGER,
+    conditional statement about the cycles where the answer can be multiples
+    out - see this module's header for the measured table.
+
+    ⚠️ AND IT IS NOT KEYED ON WHETHER THE TRADE WAS CAPPED. `arbitrage`'s own
+    sentence says "SIZED BY THE CAPACITY-TARIFF GUARD" only when the headroom
+    came out BELOW the ask - which in a shadow run is the START of the
+    quarter, where the two runs still agree. By the end of the quarter
+    `900/remaining` has multiplied the headroom past the ask, the trade is
+    NOT capped, the sentence is silent and the recorded number is at its most
+    wrong. A caveat keyed on that sentence would be quietest exactly where it
+    is needed loudest. `test_arbitrage.py` part 3d-8 drives that.
+    """
+    head = why(opts, control_started=control_started)
+    if not engaged(opts, control_started=control_started):
+        return head
+    if would_w is None:
+        return (f"{head}. No decision yet, the inverters stay at "
+                f"{WIRE_W:.0f} W.")
+    # ⚠️ THE THOUSANDS SEPARATOR IS SWAPPED ON THE NUMBER ALONE. Applied to
+    # the whole sentence it ate the comma out of `head` - and `head` is the
+    # half that says WHICH RUNG decided, which is the claim MUTATION.md's
+    # masking rule says must survive.
+    num = f"{float(would_w):+,.0f}".replace(",", " ")
+    out = (f"{head}. This cycle it would ask for {num} W, the inverters stay "
+           f"at {WIRE_W:.0f} W.")
+    if sized_from_meter:
+        out += f" {SIZED_FROM_METER}"
+    if reason:
+        out += f" Why: {reason}."
+    return out
+
+
+def log_line(*, would_w: float, reason: str, sized_from_meter: bool) -> str:
+    """The action-log line for one change of shadow decision.
+
+    ⚠️ IT IS A FUNCTION FOR THE REASON `words()` IS ONE, AND SAFETY-47 LEARNED
+    IT THE EXPENSIVE WAY. This sentence used to be an f-string inside
+    `Controller._shadow_settle()`. Deleting the caveat from it there left all
+    29 files GREEN - the only check that could see the line drove a fixture
+    with `meter_source: off`, where no arbitrage decision and therefore no
+    caveat can ever be reached. A sentence assembled at a call site is a
+    sentence no check can grade, and the page would have said one thing while
+    the record a later analysis reads said another.
+
+    ⚠️ AND IT IS THE SAME `SIZED_FROM_METER` CONSTANT THE ROW CARRIES, not a
+    second wording of it. Two sentences meaning one thing is how the two
+    surfaces start disagreeing about which cycles are caveated.
+    """
+    out = (f"SHADOW: would have commanded {float(would_w):+.0f} W ON THIS "
+           f"CYCLE - {reason}")
+    if sized_from_meter:
+        out += f" {SIZED_FROM_METER}"
+    return out
+
+
+def banner(opts: dict, *, control_started: bool, latched: tuple = ()) -> tuple:
+    """`(level, text)` for the top of the status page, or `None` when live.
+
+    ⚠️ IT GOES RED FOR A STANDING LATCH. The shadow banner sits ABOVE every
+    other branch of the cascade, because "the battery is not controlled" is
+    the one sentence that may never be displaced - but a failsafe latch that
+    is up while the controller is inert is up when it stops being inert. So the
+    banner says a safety stop outlasts shadow mode, and each latch keeps its
+    own red row below, which names it and says how it clears. The words are
+    `messages.banner_shadow()`'s (UX-09); `latched` names them for callers.
+    """
+    if not engaged(opts, control_started=control_started):
+        return None
+    return ("bad" if latched else "warn", messages.banner_shadow(bool(latched)))
+
+
+def problems(opts: dict) -> list:
+    """`validate.py`'s rule: `shadow_mode` must be one of the three values.
+
+    ⚠️ THE SENTENCE SPELLS `shadow_mode`. `configui.problems_by_field()` files
+    a refusal under the field whose key its text contains; a rule that never
+    names a key lands in the page's top-level block instead, where the operator
+    cannot see which control is wrong. UX-02's whole point is that the shipped
+    validator is the only rule surface, so the rule has to be readable there.
+
+    ⚠️ AND IT IS A REFUSAL RATHER THAN A COERCION. `mode()` resolves an
+    unreadable value to shadow, which is the safe direction but is also a
+    SILENT reinterpretation of what the operator wrote - and an install left in
+    shadow mode by a typo commands nothing at all, indefinitely.
+    """
+    raw = opts.get("shadow_mode", SHADOW_OPTION_DEFAULTS["shadow_mode"])
+    text = str("" if raw is None else raw).strip().lower()
+    if text in MODES:
+        return []
+    return [f"{messages.setting('shadow_mode')} is {messages.shown(raw)}. Choose "
+            + ", ".join(f"'{m}'" for m in MODES[:-1])
+            + f" or '{MODES[-1]}'."]

goodwe_controller/app/static/app.css

@@ -0,0 +1,226 @@
+/* UX-13 page styles. Colours follow the approved mockup (UX-13-mockup.html,
+   version 2) and prefers-color-scheme. No web fonts, no external files. */
+:root{
+  --bg:#f3f4f6;--card:#ffffff;--ink:#1b1d21;--muted:#5b626c;--faint:#8a919b;--line:#e2e5e9;
+  --accent:#1c64d9;--accent-soft:#e6efff;--on-accent:#ffffff;
+  --ok:#17773a;--ok-bg:#e6f4eb;--warn:#955300;--warn-bg:#fcefd9;--bad:#c02626;--bad-bg:#fce8e8;--info:#5b626c;--info-bg:#eceef1;
+  --solar:#c98a00;--house:#6c47c2;--grid:#56657a;--batt:#17773a;
+  --cheap:#8fcca4;--dear:#f0ad72;--mid:#cfd5dc;--track:#dde1e6;--shadow:0 1px 2px rgba(0,0,0,.05);
+}
+@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
+  --bg:#111317;--card:#1a1d23;--ink:#e7e9ec;--muted:#a2a9b3;--faint:#7c848f;--line:#2b3038;
+  --accent:#6ea2ff;--accent-soft:#1d2a44;--on-accent:#0b1220;
+  --ok:#7ccf98;--ok-bg:#15291d;--warn:#f3c16b;--warn-bg:#2e2412;--bad:#f28b82;--bad-bg:#3a1a19;--info:#a2a9b3;--info-bg:#22262d;
+  --solar:#f0c04a;--house:#b39cf0;--grid:#9fb0c6;--batt:#7ccf98;
+  --cheap:#3f7d56;--dear:#9a5a26;--mid:#3a414b;--track:#343a44;--shadow:none;
+}}
+:root[data-theme="dark"]{
+  --bg:#111317;--card:#1a1d23;--ink:#e7e9ec;--muted:#a2a9b3;--faint:#7c848f;--line:#2b3038;
+  --accent:#6ea2ff;--accent-soft:#1d2a44;--on-accent:#0b1220;
+  --ok:#7ccf98;--ok-bg:#15291d;--warn:#f3c16b;--warn-bg:#2e2412;--bad:#f28b82;--bad-bg:#3a1a19;--info:#a2a9b3;--info-bg:#22262d;
+  --solar:#f0c04a;--house:#b39cf0;--grid:#9fb0c6;--batt:#7ccf98;
+  --cheap:#3f7d56;--dear:#9a5a26;--mid:#3a414b;--track:#343a44;--shadow:none;
+}
+*{box-sizing:border-box}
+[hidden]{display:none!important}
+html{-webkit-text-size-adjust:100%}
+body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;overflow-x:hidden}
+button,input,select{font:inherit;color:inherit}
+a{color:var(--accent)}
+:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
+.top{display:flex;align-items:center;gap:12px;padding:12px 16px 8px;max-width:820px;margin:0 auto}
+.logo{width:36px;height:36px;border-radius:10px;background:var(--accent-soft);display:grid;place-items:center;color:var(--accent);flex:none}
+.app{font-weight:700;font-size:17px;line-height:1.2}
+.pill{display:flex;flex-wrap:wrap;align-items:center;gap:0 6px;font-size:13px;color:var(--muted)}
+.dot{width:8px;height:8px;border-radius:50%;background:var(--ok);flex:none}
+.dot.warn{background:var(--warn)}.dot.bad{background:var(--bad)}
+.tabs{display:flex;gap:4px;max-width:820px;margin:0 auto;padding:0 16px;border-bottom:1px solid var(--line)}
+.tab{border:0;background:none;padding:10px 12px;border-bottom:2px solid transparent;color:var(--muted);cursor:pointer;display:flex;align-items:center;gap:6px;min-height:44px;position:relative}
+.tab[aria-selected="true"]{color:var(--accent);border-bottom-color:var(--accent);font-weight:600}
+.tab svg{width:20px;height:20px}
+.badge{font-size:11px;font-weight:700;background:var(--warn);color:var(--card);border-radius:9px;padding:0 6px;line-height:18px}
+.badge.bad{background:var(--bad)}
+@media (max-width:640px){
+  .tabs{position:fixed;bottom:0;left:0;right:0;z-index:20;background:var(--card);border-top:1px solid var(--line);border-bottom:0;padding:0 4px env(safe-area-inset-bottom);justify-content:space-around;gap:0}
+  .tab{flex-direction:column;gap:0;font-size:11px;padding:6px 4px;border-bottom:0;border-top:2px solid transparent;flex:1;min-width:0}
+  .tab[aria-selected="true"]{border-top-color:var(--accent)}
+  .tab .badge{position:absolute;top:2px;left:calc(50% + 6px)}
+  .wrap{padding-bottom:96px!important}
+}
+.wrap{max-width:820px;margin:0 auto;padding:16px 16px 40px}
+h2{font-size:15px;margin:0 0 10px;font-weight:650}
+.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px;margin-bottom:12px;box-shadow:var(--shadow)}
+.muted{color:var(--muted)} .small{font-size:13px} .tiny{font-size:12px}
+.row{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
+.spread{justify-content:space-between}
+.grow{flex:1 1 auto;min-width:0}
+.banner{border-radius:12px;padding:12px 14px;margin-bottom:12px;display:flex;gap:10px;align-items:flex-start;font-weight:600}
+.banner .ic{flex:none;margin-top:2px}
+.b-ok{background:var(--ok-bg);color:var(--ok)} .b-warn{background:var(--warn-bg);color:var(--warn)} .b-bad{background:var(--bad-bg);color:var(--bad)}
+.banner small{display:block;font-weight:400;color:var(--ink);margin-top:2px}
+.tiles{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px}
+@media (max-width:640px){.tiles{grid-template-columns:repeat(2,minmax(0,1fr))}}
+.tile{border:1px solid var(--line);border-radius:10px;padding:10px;min-width:0}
+.tile .lab{font-size:13px;color:var(--muted);display:flex;align-items:center;gap:6px}
+.tile .val{font-size:22px;font-weight:700;font-variant-numeric:tabular-nums;line-height:1.25;margin-top:2px}
+.tile .val small{font-size:13px;font-weight:500;color:var(--muted)}
+.tile .sub{font-size:12px;color:var(--muted)}
+.sw-solar{color:var(--solar)} .sw-house{color:var(--house)} .sw-grid{color:var(--grid)} .sw-batt{color:var(--batt)}
+.brow{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:2px 10px;padding:10px 0;border-top:1px solid var(--line)}
+.brow:first-child{border-top:0}
+.lvl{height:10px;background:var(--track);border-radius:6px;overflow:hidden;grid-column:1/-1;margin:4px 0 2px}
+.lvl>i{display:block;height:100%;background:var(--batt);border-radius:6px}
+.lvl.none>i{background:var(--faint)}
+/* the plan chart */
+.chart{position:relative;margin:18px 0 4px}
+.bars{display:flex;align-items:flex-end;gap:2px;height:72px}
+.bars i{flex:1;border-radius:3px 3px 0 0;background:var(--mid);min-width:0}
+.bars i.cheap{background:var(--cheap)}
+/* not by colour alone: expensive hours are striped, estimates are faded */
+.bars i.dear{background:repeating-linear-gradient(135deg,var(--dear) 0 4px,color-mix(in srgb,var(--dear) 60%,var(--card)) 4px 7px)}
+.bars i.est{opacity:.55}
+.bars i.none{background:none;border-bottom:2px dotted var(--faint);height:2px!important}
+.lane{position:relative;height:18px;margin-top:4px;background:var(--bg);border-radius:4px}
+.lane b{position:absolute;top:2px;bottom:2px;border-radius:3px;min-width:3px}
+.lane .house{background:repeating-linear-gradient(90deg,var(--mid) 0 6px,transparent 6px 9px);top:6px;bottom:6px}
+.lane .grid{background:var(--accent)}
+.lane .give{background:repeating-linear-gradient(135deg,var(--house) 0 4px,color-mix(in srgb,var(--house) 55%,var(--card)) 4px 7px)}
+.lane .cycle{background:repeating-linear-gradient(90deg,var(--warn) 0 3px,var(--warn-bg) 3px 6px)}
+.lane .peak{background:var(--bad)}
+.lanelab{font-size:12px;color:var(--muted);margin-top:6px}
+.nowline{position:absolute;top:-4px;bottom:0;width:2px;background:var(--ink);opacity:.7;pointer-events:none}
+.nowline span{position:absolute;top:-15px;left:-10px;font-size:10px}
+.axis{display:flex;justify-content:space-between;font-size:11px;color:var(--faint);margin-top:4px}
+.legend{display:flex;flex-wrap:wrap;gap:4px 12px;font-size:12px;color:var(--muted);margin-top:8px}
+.legend span{display:inline-flex;align-items:center;gap:5px}
+.legend i{width:14px;height:10px;border-radius:2px;display:inline-block}
+.legend i.house{background:repeating-linear-gradient(90deg,var(--mid) 0 4px,transparent 4px 6px)}
+ul.plain{list-style:none;margin:8px 0 0;padding:0}
+ul.plain li{padding:6px 0;border-top:1px solid var(--line)}
+ul.plain li:first-child{border-top:0}
+.meter{height:12px;background:var(--track);border-radius:6px;overflow:hidden;margin:8px 0 4px}
+.meter i{display:block;height:100%;background:var(--accent)}
+.meter i.warn{background:var(--warn)} .meter i.bad{background:var(--bad)}
+.alert{display:flex;gap:10px;padding:10px 0;border-top:1px solid var(--line)}
+.alert:first-child{border-top:0}
+.sev{flex:none;width:24px;height:24px;border-radius:50%;display:grid;place-items:center;font-size:13px;font-weight:800}
+.sev.warning{background:var(--warn-bg);color:var(--warn)} .sev.alarm{background:var(--bad-bg);color:var(--bad)} .sev.info{background:var(--info-bg);color:var(--info)} .sev.ok{background:var(--ok-bg);color:var(--ok)}
+.alert .t{font-weight:600}
+.btn{border:1px solid var(--line);background:var(--card);padding:9px 14px;border-radius:10px;cursor:pointer;min-height:44px}
+.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent);font-weight:600}
+.btn.danger{color:var(--bad);border-color:var(--bad)}
+.btn:disabled{opacity:.5;cursor:not-allowed}
+a.btn{display:inline-flex;align-items:center;text-decoration:none;color:var(--ink)}
+details.more{margin-top:12px;border-top:1px solid var(--line)}
+details.more>summary{cursor:pointer;padding:10px 0;color:var(--accent);font-size:14px;min-height:44px;display:flex;align-items:center}
+table.rows{width:100%;border-collapse:collapse;font-size:13px}
+table.rows td{padding:6px 0;border-bottom:1px solid var(--line);vertical-align:top}
+table.rows td:last-child{text-align:right;font-variant-numeric:tabular-nums;font-weight:600;padding-left:12px;overflow-wrap:anywhere}
+table.rows tr:last-child td{border-bottom:0}
+ul.checks{margin:6px 0 0;padding-left:0;list-style:none;font-size:13px}
+ul.checks li{margin:3px 0}
+.c-ok{color:var(--ok)} .c-warn{color:var(--warn)} .c-bad{color:var(--bad)}
+.kv{display:grid;grid-template-columns:auto minmax(0,1fr);gap:4px 12px;font-size:14px;margin-top:10px}
+.kv dt{color:var(--muted)} .kv dd{margin:0}
+#toast{position:fixed;left:50%;transform:translateX(-50%);bottom:24px;z-index:30;background:var(--ink);color:var(--bg);padding:10px 14px;border-radius:10px;font-size:14px;max-width:calc(100% - 32px);opacity:0;pointer-events:none;transition:opacity .2s}
+#toast.show{opacity:1}
+@media (max-width:640px){#toast{bottom:84px}}
+dialog{border:1px solid var(--line);border-radius:14px;background:var(--card);color:var(--ink);max-width:min(420px,calc(100% - 32px));padding:18px}
+dialog::backdrop{background:rgba(0,0,0,.45)}
+@media (prefers-reduced-motion:reduce){*{transition:none!important}}
+.tip{position:fixed;z-index:40;background:var(--ink);color:var(--bg);font-size:12px;line-height:1.35;padding:6px 8px;border-radius:8px;pointer-events:none;max-width:240px;opacity:0;transition:opacity .1s;box-shadow:0 2px 8px rgba(0,0,0,.25);left:0;top:0}
+.tip.show{opacity:1}
+.tip b{display:block;font-weight:700}
+.tip span{display:block}
+.chart [data-tip]{cursor:default}
+.chart [data-tip]:hover,.chart [data-tip]:focus,.chart .hot{outline:2px solid var(--ink);outline-offset:-1px}
+.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
+/* UX-13 P2: Settings, the Installer view (mockup version 2) */
+.btn.link{border:0;background:none;color:var(--accent);padding:6px 0;min-height:0}
+.search{width:100%;border:1px solid var(--line);background:var(--card);border-radius:10px;padding:10px 12px;min-height:44px;margin-bottom:10px}
+.key{font:11px/1.3 ui-monospace,SFMono-Regular,Menlo,monospace;color:var(--faint);overflow-wrap:anywhere}
+.chip{display:inline-flex;align-items:center;gap:4px;font-size:12px;border-radius:999px;padding:1px 8px;background:var(--info-bg);color:var(--muted);white-space:nowrap}
+.chip.now{background:var(--ok-bg);color:var(--ok)} .chip.rs{background:var(--warn-bg);color:var(--warn)}
+.chip.bad{background:var(--bad-bg);color:var(--bad)} .chip.changed{background:var(--accent-soft);color:var(--accent)}
+details.grp{background:var(--card);border:1px solid var(--line);border-radius:12px;margin-bottom:10px;box-shadow:var(--shadow)}
+details.grp>summary{list-style:none;cursor:pointer;padding:14px;display:flex;gap:10px;align-items:center;min-height:56px;flex-wrap:wrap}
+details.grp>summary::-webkit-details-marker{display:none}
+details.grp>summary .grow{flex:1 1 200px}
+details.grp>summary .gdesc{display:block}
+details.grp>summary .chev{transition:transform .15s;flex:none;font-size:22px;line-height:1;width:18px;text-align:center;color:var(--muted)}
+details.grp[open]>summary .chev{transform:rotate(90deg)}
+.gchips,.gbadge{display:inline-flex;flex-wrap:wrap;gap:4px}
+details.grp .body{padding:0 14px 8px}
+details.sub{border-top:1px solid var(--line);margin-top:4px}
+details.sub>summary{cursor:pointer;padding:10px 0;color:var(--accent);font-size:14px;min-height:44px;display:flex;align-items:center}
+.subhead{font-size:12px;text-transform:uppercase;letter-spacing:.04em;color:var(--faint);margin:14px 0 0;font-weight:700}
+.f{padding:12px 0;border-top:1px solid var(--line);min-width:0}
+.part>.f:first-child,.subhead+.f{border-top:0}
+.f .lbl{font-weight:600;font-size:14px}
+.f .help{font-size:13px;color:var(--muted);margin-top:4px}
+.f .ctl{margin-top:8px;min-width:0}
+.f.inline{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:4px 12px;align-items:start}
+.f.inline .ctl{margin-top:0;grid-row:1;grid-column:2}
+.f.inline .help,.f.inline .msgs{grid-column:1/-1}
+.f.changed>.head .lbl::after{content:" •";color:var(--accent)}
+.msg{font-size:13px;margin-top:6px;display:flex;gap:6px;align-items:flex-start;border-radius:8px;padding:6px 8px;overflow-wrap:anywhere}
+.msg .mi{font-weight:800;flex:none}
+.msg.bad{background:var(--bad-bg);color:var(--bad)} .msg.warn{background:var(--warn-bg);color:var(--warn)} .msg.info{background:var(--info-bg);color:var(--info)}
+.f.has-bad .ctl select,.f.has-bad .ctl input,.f.has-bad .ent-btn{border-color:var(--bad)}
+.switch{position:relative;width:52px;height:44px;border:0;background:none;cursor:pointer;flex:none;padding:0}
+.switch::before{content:"";position:absolute;left:2px;top:8px;width:48px;height:28px;border-radius:14px;background:var(--track);transition:background .15s}
+.switch::after{content:"";position:absolute;top:11px;left:5px;width:22px;height:22px;border-radius:50%;background:#fff;box-shadow:0 1px 2px rgba(0,0,0,.3);transition:left .15s}
+.switch[aria-checked="true"]::before{background:var(--accent)}
+.switch[aria-checked="true"]::after{left:25px}
+.swrap{display:inline-flex;align-items:center;gap:8px;min-height:44px}
+.swtext{font-size:13px;color:var(--muted)}
+select.sel,input.txt,input.num{border:1px solid var(--line);background:var(--card);border-radius:10px;padding:9px 10px;min-height:44px;max-width:100%}
+select.sel{width:100%}
+.row>select.sel{width:auto;flex:1 1 200px}
+input.num{width:110px;text-align:right;font-variant-numeric:tabular-nums}
+input.txt{width:100%}
+input:disabled{opacity:.6}
+.seg{display:inline-flex;border:1px solid var(--line);border-radius:10px;overflow:hidden;max-width:100%;flex-wrap:wrap}
+.seg button{border:0;background:var(--card);padding:8px 12px;min-height:44px;cursor:pointer;border-left:1px solid var(--line)}
+.seg button:first-child{border-left:0}
+.seg button[aria-checked="true"]{background:var(--accent-soft);color:var(--accent);font-weight:600}
+.choice{display:flex;gap:10px;align-items:flex-start;border:1px solid var(--line);border-radius:10px;padding:10px 12px;margin-top:8px;cursor:pointer;width:100%;text-align:left;background:var(--card);min-height:44px}
+.choice[aria-checked="true"]{border-color:var(--accent);background:var(--accent-soft)}
+.choice .rad{flex:none;width:18px;height:18px;border-radius:50%;border:2px solid var(--faint);margin-top:2px}
+.choice[aria-checked="true"] .rad{border:5px solid var(--accent)}
+.slider{display:flex;align-items:center;gap:10px;width:100%}
+.slider input[type=range]{flex:1;min-width:0;accent-color:var(--accent);height:28px}
+.unit{color:var(--muted);font-size:13px;white-space:nowrap}
+.ent-btn{width:100%;text-align:left;border:1px solid var(--line);background:var(--card);border-radius:10px;padding:8px 10px;min-height:44px;cursor:pointer;display:flex;gap:8px;align-items:center}
+.ent-btn .grow{min-width:0}
+.ent-btn .grow>div{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
+.ent-pop{border:1px solid var(--line);border-radius:10px;margin-top:6px;background:var(--card);overflow:hidden}
+.ent-pop input[type=search]{border:0;border-bottom:1px solid var(--line);width:100%;padding:10px;background:var(--card);min-height:44px}
+.ent-note{padding:6px 10px}
+.ent-list{max-height:240px;overflow:auto}
+.ent-opt{display:flex;gap:8px;align-items:center;width:100%;border:0;border-bottom:1px solid var(--line);background:none;text-align:left;padding:8px 10px;cursor:pointer;min-height:44px}
+.ent-opt:hover,.ent-opt:focus{background:var(--accent-soft)}
+.ent-opt .grow{min-width:0}
+.ent-opt .grow>div{overflow-wrap:anywhere}
+.ent-opt .v{font-variant-numeric:tabular-nums;font-size:13px;color:var(--muted);white-space:nowrap}
+.ent-all{display:flex;gap:6px;padding:6px 10px;align-items:center;min-height:44px}
+.elist .erow{padding:6px 0;border-bottom:1px dashed var(--line)}
+.elist>.btn{margin-top:8px}
+.inv{border:1px solid var(--line);border-radius:10px;padding:0 12px;margin:10px 0}
+.inv>.hd{display:flex;align-items:center;gap:8px;padding:10px 0;border-bottom:1px solid var(--line);font-weight:600;flex-wrap:wrap}
+.inv>.f:nth-child(2){border-top:0}
+.invs>.btn{margin:4px 0 8px}
+#savebar{position:fixed;left:0;right:0;bottom:0;z-index:15}
+#savebar .in{max-width:820px;margin:0 auto 10px;padding:10px 12px;background:var(--ink);color:var(--bg);border-radius:12px;display:flex;flex-wrap:wrap;gap:8px;align-items:center;box-shadow:0 4px 16px rgba(0,0,0,.25);width:calc(100% - 32px)}
+#savebar .btn{min-height:44px;padding:6px 12px;background:transparent;color:var(--bg);border-color:rgba(127,127,127,.6)}
+#savebar .btn.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent)}
+@media (max-width:640px){#savebar{bottom:62px}}
+#s-set{padding-bottom:80px}
+/* UX-13 P4: the setup wizard */
+.steps{display:flex;gap:4px;margin:4px 0 12px}
+.steps i{flex:1;height:6px;border-radius:3px;background:var(--track)}
+.steps i.done{background:var(--accent)} .steps i.cur{background:var(--accent);opacity:.55}
+.msg.ok{background:var(--ok-bg);color:var(--ok)}
+.sev.bad{background:var(--bad-bg);color:var(--bad)} .sev.warn{background:var(--warn-bg);color:var(--warn)}
+.checklist li{display:flex;gap:8px;align-items:flex-start;overflow-wrap:anywhere}
+.kettle .row{margin-top:8px}

goodwe_controller/app/static/app.js

@@ -0,0 +1,377 @@
+"use strict";
+/* UX-13 P1: the page shell and the Home screen. Plain JS, no framework, no
+   external files. Every URL is relative, because ingress serves the add-on
+   under a generated path prefix. Every word comes from app/ui_text (fixed
+   labels) or from /status (sentences built by app/homeview.py), so STYLE.md
+   is checked in Python. Data is always set as text, never as HTML. */
+(function () {
+  const T = JSON.parse(document.getElementById("ui-text").textContent).home;
+  const $ = (s) => document.querySelector(s);
+  const t = (path) => path.split(".").reduce((o, k) => (o == null ? o : o[k]), T);
+  function h(tag, attrs, ...kids) {
+    const e = document.createElement(tag);
+    for (const k in attrs || {}) {
+      const v = attrs[k];
+      if (v === false || v == null) continue;
+      if (k === "class") e.className = v;
+      else if (k === "style") e.style.cssText = v;
+      else if (k.startsWith("on")) e.addEventListener(k.slice(2), v);
+      else e.setAttribute(k, v === true ? "" : v);
+    }
+    for (const c of kids.flat()) {
+      if (c == null || c === false) continue;
+      e.append(c.nodeType ? c : document.createTextNode(String(c)));
+    }
+    return e;
+  }
+  const kw = (w) => (Math.abs(Number(w)) / 1000).toFixed(1);
+  const eur = (v) => "€" + Number(v).toFixed(2);
+
+  // Fixed labels from ui_text.
+  document.querySelectorAll("[data-t]").forEach((e) => { e.textContent = t(e.dataset.t) || ""; });
+  document.querySelectorAll("[data-t-label]").forEach((e) => { e.setAttribute("aria-label", t(e.dataset.tLabel) || ""); });
+
+  let S = null;              // the last /status
+  let busy = false;
+
+  /* ---------------- toast and confirm dialog ---------------- */
+  function toast(text) {
+    const e = $("#toast"); e.textContent = text; e.classList.add("show");
+    clearTimeout(toast.timer); toast.timer = setTimeout(() => e.classList.remove("show"), 2600);
+  }
+  let onYes = null;
+  // `key` names Home's words in ui_text, or is {name, description, yes}.
+  function ask(key, fn) {
+    const w = typeof key === "string" ? t("dialog." + key) : key;
+    $("#dlg-t").textContent = w.name;
+    $("#dlg-b").textContent = w.description;
+    $("#dlg-yes").textContent = w.yes;
+    onYes = fn;
+    const d = $("#dlg");
+    if (typeof d.showModal === "function") d.showModal(); else if (window.confirm($("#dlg-t").textContent)) fn();
+  }
+  $("#dlg-no").addEventListener("click", () => $("#dlg").close());
+  $("#dlg-yes").addEventListener("click", () => { $("#dlg").close(); if (onYes) onYes(); });
+
+  /* ---------------- data ---------------- */
+  async function getStatus() {
+    const r = await fetch("status", { cache: "no-store" });
+    if (!r.ok) throw new Error("status " + r.status);
+    return r.json();
+  }
+  async function act(what) {
+    const r = await fetch("action", { method: "POST", headers: { "Content-Type": "application/json" },
+                                      body: JSON.stringify({ action: what }) });
+    if (!r.ok) throw new Error("action " + r.status);
+    return r.json();
+  }
+  async function refresh() {
+    if (busy) return;
+    busy = true;
+    try { S = await getStatus(); render(); }
+    catch (e) { offline(); }
+    finally { busy = false; }
+  }
+
+  /* ---------------- shell ---------------- */
+  function banner(el, level, title, sub, role) {
+    el.replaceChildren(h("div", { class: "banner " + ({ ok: "b-ok", bad: "b-bad" }[level] || "b-warn"), role: role || null },
+      h("span", { class: "ic", "aria-hidden": "true" }, { ok: "✓", bad: "×" }[level] || "!"),
+      h("span", {}, title, sub ? h("small", {}, sub) : null)));
+  }
+  function offline() {
+    banner($("#home-banner"), "bad", t("offline.name"), t("offline.description"), "alert");
+    $("#pill").replaceChildren(h("span", { class: "dot bad" }), h("span", {}, t("offline.name")));
+  }
+  function renderPill() {
+    const st = S.state || null;
+    const dot = st ? ({ running: "", shadow: " warn", stopped: " warn", warning: " warn", alarm: " bad" }[st.kind] ?? " warn")
+                   : (S.level === "ok" ? "" : S.level === "bad" ? " bad" : " warn");
+    const words = st ? [st.pill, st.ran].filter(Boolean).join(". ") : S.banner;
+    $("#pill").replaceChildren(h("span", { class: "dot" + dot, "aria-hidden": "true" }), h("span", {}, words));
+  }
+
+  function render() {
+    renderPill();
+    const structured = S.now && S.plan && !S.home_error;
+    banner($("#home-banner"), S.level, S.banner, structured ? S.state.sub : "", S.level === "bad" ? "alert" : null);
+    ["#c-now", "#c-plan", "#c-peak", "#c-attn"].forEach((id) => { $(id).hidden = !structured; });
+    if (structured) { renderNow(); renderPlan(); renderPeak(); renderAttention(); }
+    renderControl(structured);
+    renderDetails(!structured);
+    renderBatteries();
+  }
+
+  /* ---------------- Home: now ---------------- */
+  function val(id, w, show) {
+    const e = $(id);
+    if (w == null || !show) { e.textContent = "–"; return; }
+    e.replaceChildren(kw(w) + " ", h("small", {}, "kW"));
+  }
+  function levelBar(pct, label) {
+    const known = pct != null;
+    return h("div", { class: "lvl" + (known ? "" : " none"), role: "img",
+                      "aria-label": label + " " + (known ? Math.round(pct) + " %" : "–") },
+      h("i", { style: "width:" + (known ? Math.max(0, Math.min(100, pct)) : 0) + "%" }));
+  }
+  function renderNow() {
+    const n = S.now;
+    val("#v-solar", n.solar_w, n.has_solar); $("#sub-solar").textContent = n.lines.solar;
+    val("#v-house", n.house_w, true); $("#sub-house").textContent = n.lines.house;
+    val("#v-grid", n.grid_w, true); $("#sub-grid").textContent = n.lines.grid;
+    val("#v-batt", n.batt_w, true); $("#sub-batt").textContent = n.lines.batt;
+    $("#home-batts").replaceChildren(...S.batteries.map((b) => h("div", { class: "brow" },
+      h("div", {}, h("strong", {}, b.name), h("span", { class: "muted small" }, " · " + b.mode)),
+      h("div", { class: "small", style: "font-variant-numeric:tabular-nums" }, b.level_pct == null ? "–" : Math.round(b.level_pct) + " %"),
+      levelBar(b.level_pct, b.name),
+      h("div", { class: "small muted", style: "grid-column:1/-1" }, b.now))));
+  }
+
+  /* ---------------- Home: today's plan ---------------- */
+  const LEGEND = [["cheap", "background:var(--cheap)"], ["dear", "background:repeating-linear-gradient(135deg,var(--dear) 0 3px,transparent 3px 5px)"],
+                  ["grid", "background:var(--accent)"], ["give", "background:repeating-linear-gradient(135deg,var(--house) 0 3px,transparent 3px 5px)"],
+                  ["cycle", "background:repeating-linear-gradient(90deg,var(--warn) 0 2px,transparent 2px 4px)"],
+                  ["peak", "background:var(--bad)"], ["house", null]];
+  function tipText(lines) { return lines.filter(Boolean).join(" "); }
+  function chartItem(tag, cls, style, title, lines) {
+    return h(tag, { class: cls, style: style, tabindex: "-1", role: "img", "aria-label": tipText([title + "."].concat(lines)),
+                    "data-tip": JSON.stringify([title].concat(lines.filter(Boolean))) });
+  }
+  function roving(group) {
+    const items = [...group.querySelectorAll("[data-tip]")];
+    items.forEach((el, i) => {
+      el.tabIndex = i === 0 ? 0 : -1;
+      el.addEventListener("keydown", (e) => {
+        const d = { ArrowRight: 1, ArrowLeft: -1, Home: -1e9, End: 1e9 }[e.key];
+        if (d === undefined) return;
+        e.preventDefault();
+        const j = Math.max(0, Math.min(items.length - 1, i + d));
+        items[i].tabIndex = -1; items[j].tabIndex = 0; items[j].focus();
+      });
+    });
+  }
+  function renderPlan() {
+    const p = S.plan;
+    $("#verdict").textContent = p.verdict;
+    $("#plan-head").textContent = p.head;
+    const hours = p.hours || 24;
+    const bars = $("#bars");
+    const known = p.prices.filter((b) => b.eur_kwh != null);
+    const mx = Math.max(0.01, ...known.map((b) => Math.abs(b.eur_kwh)));
+    bars.setAttribute("aria-label", t("plan.name"));
+    bars.replaceChildren(...p.prices.map((b) => {
+      const title = b.label + " " + t("plan.time_to") + " " + b.end_label;
+      if (b.eur_kwh == null) return chartItem("i", "none", "", title, [t("plan.none_tip") + "."]);
+      const kind = b.kind === "cheap" ? ", " + t("plan.cheap_tip") : b.kind === "dear" ? ", " + t("plan.dear_tip") : "";
+      const est = (b.points > 1 ? ", " + t("plan.average_tip") : "") + (b.estimate ? ", " + t("plan.estimate_tip") : "");
+      return chartItem("i", (b.kind || "mid") + (b.estimate ? " est" : ""),
+                       "height:" + Math.max(4, Math.round(Math.abs(b.eur_kwh) / mx * 100)) + "%",
+                       title, [eur(b.eur_kwh) + " " + t("plan.per_kwh") + kind + est + "."]);
+    }));
+    roving(bars);
+    $("#no-prices").hidden = known.length > 0;
+    const lanes = $("#lanes");
+    lanes.replaceChildren();
+    S.batteries.forEach((b, i) => {
+      const lane = h("div", { class: "lane", role: "group", "aria-label": b.name });
+      const runs = p.runs.filter((r) => r.battery === i).sort((a, z) => (a.kind === "house" ? -1 : 0) - (z.kind === "house" ? -1 : 0));
+      for (const r of runs) {
+        if (r.end_h <= r.start_h) continue;
+        lane.append(chartItem("b", r.kind, "left:" + (r.start_h / hours * 100) + "%;width:" + ((r.end_h - r.start_h) / hours * 100) + "%",
+                              b.name + ", " + r.from + " " + t("plan.time_to") + " " + r.to, [r.what, r.why, r.amount]));
+      }
+      lanes.append(h("div", { class: "lanelab", "aria-hidden": "true" }, b.name), lane);
+      roving(lane);
+    });
+    const nl = $("#nowline");
+    nl.style.left = Math.max(0, Math.min(100, p.now_h / hours * 100)) + "%";
+    const used = new Set(p.runs.map((r) => r.kind));
+    known.forEach((b) => used.add(b.kind));
+    $("#legend").replaceChildren(...LEGEND.filter(([k]) => used.has(k)).map(([k, css]) =>
+      h("span", {}, h("i", { class: k === "house" ? "house" : null, style: css, "aria-hidden": "true" }), t("plan." + k))));
+    const list = [];
+    S.batteries.forEach((b, i) => {
+      for (const r of p.runs.filter((x) => x.battery === i && x.kind !== "house")) {
+        list.push(h("li", {}, h("strong", {}, b.name + ", " + r.from + " " + t("plan.time_to") + " " + r.to + ": "), tipText([r.what, r.why, r.amount])));
+      }
+      const house = p.runs.find((x) => x.battery === i && x.kind === "house");
+      if (house) list.push(h("li", {}, h("strong", {}, b.name + ": "), tipText([house.what, house.why])));
+    });
+    for (const line of p.lines) list.push(h("li", {}, line));
+    $("#plan-list").replaceChildren(...list);
+    $("#price-line").textContent = [p.price_line, p.tomorrow_line, p.region_line].filter(Boolean).join(" ");
+  }
+
+  /* ---------------- tooltips: hover, tap and keyboard focus ---------------- */
+  (function () {
+    const tip = $("#tip"); let hot = null;
+    const hide = () => { tip.classList.remove("show"); if (hot) hot.classList.remove("hot"); hot = null; };
+    function show(el, x, y) {
+      if (hot && hot !== el) hot.classList.remove("hot");
+      hot = el; el.classList.add("hot");
+      const lines = JSON.parse(el.dataset.tip);
+      tip.replaceChildren(h("b", {}, lines[0]), ...lines.slice(1).map((l) => h("span", {}, l)));
+      tip.classList.add("show");
+      const r = tip.getBoundingClientRect();
+      let L = x + 12, T2 = y - r.height - 12;
+      if (L + r.width > innerWidth - 8) L = x - r.width - 12;
+      if (L < 8) L = 8;
+      if (T2 < 8) T2 = y + 16;
+      tip.style.left = L + "px"; tip.style.top = T2 + "px";
+    }
+    const target = (e) => e.target.closest && e.target.closest(".chart [data-tip]");
+    document.addEventListener("pointermove", (e) => {
+      if (e.pointerType === "touch") return;
+      const el = target(e);
+      if (el) show(el, e.clientX, e.clientY); else if (hot && document.activeElement !== hot) hide();
+    });
+    document.addEventListener("pointerdown", (e) => {
+      const el = target(e);
+      if (el && e.pointerType === "touch") { if (hot === el) hide(); else show(el, e.clientX, e.clientY); }
+      else if (!el) hide();
+    });
+    document.addEventListener("focusin", (e) => {
+      const el = target(e);
+      if (el) { const r = el.getBoundingClientRect(); show(el, r.left + r.width / 2, r.top); }
+    });
+    document.addEventListener("focusout", (e) => { if (target(e)) hide(); });
+    document.addEventListener("keydown", (e) => { if (e.key === "Escape") hide(); });
+    addEventListener("scroll", hide, { passive: true });
+  })();
+
+  /* ---------------- Home: peak, attention, control, details ---------------- */
+  function renderPeak() {
+    const m = S.month_peak;
+    $("#peak-month").textContent = m.month;
+    const covered = m.state !== "not_covered";
+    $("#peak-figures").hidden = !covered; $("#peak-meter").hidden = !covered;
+    $("#peak-now").textContent = m.peak_w != null ? kw(m.peak_w) + " kW"
+                                 : m.state === "unreadable" ? t("peak.unreadable") : t("peak.none");
+    $("#peak-limit").textContent = kw(m.limit_w) + " kW";
+    const pct = m.pct == null ? 0 : Math.max(0, Math.min(100, m.pct));
+    const bar = $("#peak-meter i");
+    bar.style.width = pct + "%";
+    bar.className = pct >= 100 ? "bad" : pct >= 80 ? "warn" : "";
+    $("#peak-meter").setAttribute("aria-label", t("peak.this_month") + " " + (m.pct == null ? "–" : Math.round(m.pct) + " %"));
+    $("#peak-line").textContent = m.line;
+  }
+  function renderAttention() {
+    const list = S.attention;
+    const icon = { alarm: "×", warning: "!", info: "i" };
+    $("#alerts").replaceChildren(...list.map((a) => h("div", { class: "alert" },
+      h("span", { class: "sev " + a.severity, "aria-hidden": "true" }, icon[a.severity] || "i"),
+      h("div", {}, h("div", { class: "t" }, h("span", { class: "sr" }, t("attention." + a.severity) + ": "), a.title),
+        h("div", { class: "small" }, a.body),
+        a.docs && S.control.docs_url ? h("a", { class: "tiny", href: S.control.docs_url, target: "_top", rel: "noopener" }, t("attention.details")) : null))));
+    const n = list.filter((a) => a.severity !== "info").length;
+    $("#attn-count").textContent = n ? n + " " + t("attention.to_look") : t("attention.nothing");
+    if (!list.length) $("#alerts").replaceChildren(h("div", { class: "small muted" }, t("attention.nothing")));
+    const badge = $("#attn-badge");
+    badge.textContent = n; badge.hidden = !n;
+    badge.classList.toggle("bad", list.some((a) => a.severity === "alarm"));
+  }
+  function renderControl(structured) {
+    const running = structured ? S.control.running : null;
+    const btn = $("#btn-ctl");
+    btn.textContent = running === false ? t("control.start") : t("control.stop");
+    btn.className = "btn" + (running === false ? " primary" : "");
+    $("#ctl-text").textContent = structured ? S.control.text : "";
+    $("#hint").textContent = S.hint || "";
+    const docs = $("#docs-link");
+    if (structured && S.control.docs_url) { docs.href = S.control.docs_url; docs.hidden = false; } else docs.hidden = true;
+  }
+  function renderDetails(open) {
+    $("#rows").replaceChildren(...(S.rows || []).map(([k, v]) => h("tr", {}, h("td", { class: "muted" }, k), h("td", {}, v))));
+    $("#checks").replaceChildren(...(S.checks || []).map((c) => {
+      const cls = c.ok ? (c.warn ? "c-warn" : "c-ok") : (c.warn ? "c-warn" : "c-bad");
+      const mark = c.ok ? (c.warn ? "!" : "✓") : (c.warn ? "!" : "✗");
+      return h("li", { class: cls }, mark + " " + c.text);
+    }));
+    if (open) $("#c-details").open = true;
+  }
+
+  /* ---------------- Batteries (placeholder until P3) ---------------- */
+  function renderBatteries() {
+    if (!S.batteries) { $("#bcards").replaceChildren(); return; }
+    $("#bcards").replaceChildren(...S.batteries.map((b) => h("div", { class: "card" },
+      h("div", { class: "row spread" }, h("strong", {}, b.name), h("span", { class: "small muted" }, b.capacity_kwh ? b.capacity_kwh + " kWh" : "")),
+      levelBar(b.level_pct, b.name),
+      h("dl", { class: "kv" },
+        h("dt", {}, t("batteries.level")), h("dd", {}, b.level_pct == null ? "–" : Math.round(b.level_pct) + " %"),
+        b.stored_kwh != null ? [h("dt", {}, t("batteries.stored")), h("dd", {}, b.stored_kwh.toFixed(1) + " kWh")] : null,
+        h("dt", {}, t("batteries.now")), h("dd", {}, b.now),
+        h("dt", {}, t("batteries.mode")), h("dd", {}, b.mode)))));
+  }
+
+  /* ---------------- control buttons ---------------- */
+  // The action is a toggle, so the page reads the live state first and sends
+  // nothing when control is already where the person asked it to be.
+  // One request at a time: a second confirm while the first is in flight
+  // would read the same state and toggle it back.
+  let toggling = false;
+  async function setControl(want) {
+    if (toggling) return;
+    toggling = true;
+    try {
+      const now = await getStatus();
+      if (!now.control || now.control.running !== want) await act("auto_toggle");
+      toast(want ? t("toast.started") : t("toast.stopped"));
+    } catch (e) { toast(t("toast.failed")); }
+    finally { toggling = false; }
+    refresh();
+  }
+  $("#btn-ctl").addEventListener("click", () => {
+    const running = S && S.control ? S.control.running : true;
+    if (running) ask("stop", () => setControl(false)); else ask("start", () => setControl(true));
+  });
+  async function simple(what) {
+    try { await act(what); toast(t("toast.done")); } catch (e) { toast(t("toast.failed")); }
+    refresh();
+  }
+  $("#btn-maint").addEventListener("click", () => ask("maint_start", () => simple("maint_start")));
+  $("#btn-abort").addEventListener("click", () => ask("maint_abort", () => simple("maint_abort")));
+
+  // Shared with settings.js, which loads after this file.
+  // `first`: the page opened with no route, so settings.js may open the setup
+  // wizard on a new install (UX-13 P4).
+  window.UX13 = { h, ask, toast, t, maint: (what) => ask(what, () => simple(what)), first: !location.hash };
+
+  /* ---------------- tabs: hash routes, arrow keys ---------------- */
+  const TABS = [...document.querySelectorAll(".tab")];
+  function select(tab, focus) {
+    TABS.forEach((x) => {
+      const on = x === tab;
+      x.setAttribute("aria-selected", String(on)); x.tabIndex = on ? 0 : -1;
+      document.getElementById(x.getAttribute("aria-controls")).hidden = !on;
+    });
+    if (focus) tab.focus();
+    if (location.hash !== "#" + tab.dataset.hash) history.replaceState(null, "", "#" + tab.dataset.hash);
+    schedule();
+    document.dispatchEvent(new CustomEvent("ux13:tab", { detail: tab.dataset.hash }));
+  }
+  TABS.forEach((x, i) => {
+    x.addEventListener("click", () => select(x, false));
+    x.addEventListener("keydown", (e) => {
+      const j = { ArrowRight: i + 1, ArrowLeft: i - 1 + TABS.length, Home: 0, End: TABS.length - 1 }[e.key];
+      if (j === undefined) return;
+      e.preventDefault(); select(TABS[j % TABS.length], true);
+    });
+  });
+  function fromHash() {
+    const want = (location.hash || "#home").slice(1);
+    select(TABS.find((x) => x.dataset.hash === want) || TABS[0], false);
+  }
+  addEventListener("hashchange", fromHash);
+
+  /* ---------------- polling: every 3 s while Home or Batteries shows ---------------- */
+  let timer = null;
+  function schedule() {
+    const live = !document.hidden && ($("#t-home").getAttribute("aria-selected") === "true" ||
+                                      $("#t-batt").getAttribute("aria-selected") === "true");
+    if (live && !timer) { refresh(); timer = setInterval(refresh, 3000); }
+    if (!live && timer) { clearInterval(timer); timer = null; }
+  }
+  document.addEventListener("visibilitychange", schedule);
+  fromHash();
+  refresh();
+})();

goodwe_controller/app/static/index.html

@@ -0,0 +1,155 @@
+<!doctype html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<title>Battery add-on</title>
+<style>/*APP_CSS*/</style>
+</head>
+<body>
+<header class="top">
+  <div class="logo" aria-hidden="true"><svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><rect x="3" y="7" width="16" height="10" rx="2"/><path d="M21 11v2M8 10l-2 3h4l-2 3"/></svg></div>
+  <div class="grow">
+    <div class="app" data-t="app.name"></div>
+    <div class="pill" id="pill" aria-live="polite"><span class="dot warn"></span><span>…</span></div>
+  </div>
+</header>
+
+<nav class="tabs" role="tablist" id="tabs" data-t-label="tabs.label">
+  <button class="tab" role="tab" id="t-home" aria-controls="s-home" aria-selected="true" data-hash="home"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><path d="M3 11l9-7 9 7v9a1 1 0 0 1-1 1h-5v-6H9v6H4a1 1 0 0 1-1-1z"/></svg><span data-t="tabs.home"></span><span class="badge" id="attn-badge" hidden></span></button>
+  <button class="tab" role="tab" id="t-batt" aria-controls="s-batt" aria-selected="false" data-hash="batteries" tabindex="-1"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><rect x="3" y="7" width="16" height="10" rx="2"/><path d="M21 11v2"/><rect x="5.5" y="9.5" width="7" height="5" fill="currentColor" stroke="none"/></svg><span data-t="tabs.batteries"></span></button>
+  <button class="tab" role="tab" id="t-set" aria-controls="s-set" aria-selected="false" data-hash="settings" tabindex="-1"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><path d="M4 6h10M18 6h2M4 12h4M12 12h8M4 18h12M20 18h0"/><circle cx="16" cy="6" r="2"/><circle cx="10" cy="12" r="2"/><circle cx="18" cy="18" r="2"/></svg><span data-t="tabs.settings"></span></button>
+  <button class="tab" role="tab" id="t-wiz" aria-controls="s-wiz" aria-selected="false" data-hash="setup" tabindex="-1"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><path d="M14 7l3 3M5 19l9.5-9.5 3 3L8 22H5z"/><path d="M19 2v4M17 4h4"/></svg><span data-t="tabs.setup"></span></button>
+</nav>
+
+<main class="wrap">
+
+<section class="screen" id="s-home" role="tabpanel" aria-labelledby="t-home">
+  <div id="home-banner"></div>
+
+  <div class="card" id="c-now">
+    <div class="row spread"><h2 data-t="now.name"></h2><span class="tiny muted" data-t="now.description"></span></div>
+    <div class="tiles">
+      <div class="tile"><div class="lab"><span class="sw-solar" aria-hidden="true">&#9728;</span><span data-t="now.solar"></span></div><div class="val" id="v-solar">–</div><div class="sub" id="sub-solar"></div></div>
+      <div class="tile"><div class="lab"><span class="sw-house" aria-hidden="true">&#8962;</span><span data-t="now.house"></span></div><div class="val" id="v-house">–</div><div class="sub" id="sub-house"></div></div>
+      <div class="tile"><div class="lab"><span class="sw-grid" aria-hidden="true">&#8645;</span><span data-t="now.grid"></span></div><div class="val" id="v-grid">–</div><div class="sub" id="sub-grid"></div></div>
+      <div class="tile"><div class="lab"><span class="sw-batt" aria-hidden="true">&#9646;</span><span data-t="now.batteries"></span></div><div class="val" id="v-batt">–</div><div class="sub" id="sub-batt"></div></div>
+    </div>
+    <div id="home-batts" style="margin-top:6px"></div>
+  </div>
+
+  <div class="card" id="c-plan">
+    <div class="row spread"><h2 data-t="plan.name"></h2><span class="chip tiny muted" id="verdict"></span></div>
+    <div class="small" id="plan-head"></div>
+    <div class="chart" id="chart">
+      <div class="bars" id="bars" role="group"></div>
+      <div id="lanes"></div>
+      <div class="nowline" id="nowline" aria-hidden="true"><span data-t="plan.now"></span></div>
+      <div class="axis" aria-hidden="true"><span>00:00</span><span>06:00</span><span>12:00</span><span>18:00</span><span>24:00</span></div>
+    </div>
+    <p class="tiny muted" id="no-prices" hidden data-t="plan.no_prices.description"></p>
+    <div class="legend" id="legend"></div>
+    <p class="tiny muted" style="margin:6px 0 0" data-t="plan.description"></p>
+    <h3 class="sr" data-t="plan.list"></h3>
+    <ul class="plain small" id="plan-list"></ul>
+    <p class="tiny muted" style="margin:8px 0 0" id="price-line"></p>
+  </div>
+
+  <div class="card" id="c-peak">
+    <div class="row spread"><h2 data-t="peak.name"></h2><span class="tiny muted" id="peak-month"></span></div>
+    <div class="row spread small" id="peak-figures"><span><span data-t="peak.this_month"></span>: <strong id="peak-now"></strong></span><span class="muted"><span data-t="peak.limit"></span> <span id="peak-limit"></span></span></div>
+    <div class="meter" id="peak-meter" role="img"><i style="width:0%"></i></div>
+    <div class="tiny muted" id="peak-line"></div>
+  </div>
+
+  <div class="card" id="c-attn">
+    <div class="row spread"><h2 data-t="attention.name"></h2><span class="tiny muted" id="attn-count"></span></div>
+    <div id="alerts"></div>
+  </div>
+
+  <div class="card" id="c-ctl">
+    <h2 data-t="control.name"></h2>
+    <div class="small" id="ctl-text"></div>
+    <div class="row" style="margin-top:10px">
+      <button class="btn" id="btn-ctl" type="button"></button>
+      <a class="small" id="docs-link" hidden target="_top" rel="noopener" data-t="control.docs"></a>
+    </div>
+    <div class="tiny muted" id="hint" aria-live="polite" style="margin-top:8px"></div>
+    <details class="more">
+      <summary data-t="control.more"></summary>
+      <div class="row" style="padding-bottom:6px">
+        <button class="btn" id="btn-maint" type="button" data-t="control.maint_start"></button>
+        <button class="btn danger" id="btn-abort" type="button" data-t="control.maint_abort"></button>
+      </div>
+    </details>
+  </div>
+
+  <details class="card more" id="c-details">
+    <summary data-t="details.name"></summary>
+    <table class="rows" id="rows"></table>
+    <h2 style="margin-top:12px" data-t="details.checks"></h2>
+    <ul class="checks" id="checks"></ul>
+  </details>
+</section>
+
+<section class="screen" id="s-batt" role="tabpanel" aria-labelledby="t-batt" hidden>
+  <div id="bcards"></div>
+  <div class="card">
+    <p class="small muted" style="margin:0 0 10px" data-t="batteries.description"></p>
+    <a class="btn" href="#settings" data-t="batteries.settings"></a>
+  </div>
+</section>
+
+<section class="screen" id="s-set" role="tabpanel" aria-labelledby="t-set" hidden>
+  <div class="row spread" style="margin-bottom:6px">
+    <h2 style="margin:0" data-s="name"></h2>
+    <a class="small" href="config" id="set-classic" data-s="classic"></a>
+  </div>
+  <p class="small muted" style="margin:0 0 10px" data-s="description"></p>
+  <div id="set-banner" aria-live="polite"></div>
+  <div id="set-body">
+    <input class="search" id="set-search" type="search" autocomplete="off" spellcheck="false" data-s-ph="search.description" data-s-label="search.name">
+    <div class="card" id="set-other" hidden><h2 data-s="other"></h2><ul class="plain small" id="set-other-list"></ul></div>
+    <div id="groups"><p class="small muted" data-s="loading"></p></div>
+    <p class="small muted" id="set-nomatch" hidden data-s="no_match.description"></p>
+    <p class="tiny muted" data-s="footer.description"></p>
+  </div>
+</section>
+
+<section class="screen" id="s-wiz" role="tabpanel" aria-labelledby="t-wiz" hidden>
+  <div class="card" id="wz">
+    <div class="row spread"><h2 id="wz-title" style="margin:0" data-s="setup.name"></h2><span class="tiny muted" id="wz-count"></span></div>
+    <div class="steps" id="wz-steps" aria-hidden="true"></div>
+    <p class="small muted" id="wz-desc" style="margin:0 0 6px"></p>
+    <div id="wz-banner" aria-live="polite"></div>
+    <div id="wz-body"><p class="small muted" data-s="loading"></p></div>
+    <div class="row spread" id="wz-nav" style="margin-top:14px">
+      <button class="btn" id="wz-back" type="button" data-s="setup.back"></button>
+      <button class="btn primary" id="wz-next" type="button" data-s="setup.next"></button>
+    </div>
+  </div>
+  <p class="tiny muted" data-s="setup.description"></p>
+</section>
+</main>
+
+<dialog id="dlg" aria-labelledby="dlg-t" aria-describedby="dlg-b">
+  <h2 id="dlg-t"></h2>
+  <p class="small" id="dlg-b"></p>
+  <div class="row" style="justify-content:flex-end">
+    <button class="btn" id="dlg-no" type="button" data-t="dialog.cancel"></button>
+    <button class="btn primary" id="dlg-yes" type="button"></button>
+  </div>
+</dialog>
+<div id="savebar" role="region" hidden><div class="in">
+  <span class="grow" id="sb-text" aria-live="polite"></span>
+  <button class="btn" id="sb-discard" type="button" data-s="savebar.discard"></button>
+  <button class="btn primary" id="sb-save" type="button" data-s="savebar.save"></button>
+</div></div>
+<div id="toast" role="status" aria-live="polite"></div>
+<div id="tip" class="tip" aria-hidden="true"></div>
+
+<script type="application/json" id="ui-text">/*UI_TEXT*/</script>
+<script>/*APP_JS*/</script>
+<script>/*SETTINGS_JS*/</script>
+</body>
+</html>

goodwe_controller/app/static/settings.js

@@ -0,0 +1,808 @@
+"use strict";
+/* UX-13 P2: Settings, the Installer view. It draws from /config/model's
+   `layout` (app/uilayout.py through app/uipage.py) and `ui` (the page model
+   from app/uimodel.py), so this file names no option key: keys, labels,
+   ranges and choices all arrive as data. It posts the page model back; the
+   add-on turns it into options and runs its own start checks, and nothing
+   they refuse is saved. Every word is from app/ui_text or the add-on, and
+   data is set as text, never as HTML.
+   P4: the Setup tab's wizard is the same page model, drawn one step at a
+   time from each field's `wizard` step, and saved through the same routes. */
+(function () {
+  const ROOT = JSON.parse(document.getElementById("ui-text").textContent);
+  const W = ROOT.settings;
+  const { h, ask, toast, maint } = window.UX13;
+  const $ = (s) => document.querySelector(s);
+  const ws = (path) => path.split(".").reduce((o, k) => (o == null ? o : o[k]), W);
+  const clone = (x) => (x === undefined ? undefined : JSON.parse(JSON.stringify(x)));
+  const same = (a, b) => JSON.stringify(a ?? null) === JSON.stringify(b ?? null);
+
+  document.querySelectorAll("[data-s]").forEach((e) => { e.textContent = ws(e.dataset.s) || ""; });
+  document.querySelectorAll("[data-s-ph]").forEach((e) => { e.placeholder = ws(e.dataset.sPh) || ""; });
+  document.querySelectorAll("[data-s-label]").forEach((e) => { e.setAttribute("aria-label", ws(e.dataset.sLabel) || ""); });
+  $("#savebar").setAttribute("aria-label", W.savebar.label);
+
+  let M = null;              // the last /config/model
+  let V = null;              // the page model being edited
+  let ORIG = null;           // the page model as stored
+  let FP = "";               // the stored blob's fingerprint (compare-and-swap)
+  let MSG = [];              // [{field, card, tier, text}] from the add-on
+  let DEVICE = "";
+  let LIST = null;           // the inverter list field
+  let FILLED = {};           // field key -> the preset field that fills it
+  let view = null;           // "settings" or "setup": the tab drawing V
+  let STEPS = {};            // wizard step -> refusals that block it
+  let uid = 0;
+  const ROWS = [];
+  const OPEN = new Set();
+  const UNLOCKED = new Set();
+
+  /* ---------------- the page model ---------------- */
+  const sub = (f) => f.key.slice(LIST.key.length + 1);
+  function valueIn(model, f, card) {
+    if (card == null) return model[f.key];
+    const c = (model[LIST.key] || [])[card];
+    return c ? c[sub(f)] : undefined;
+  }
+  const get = (f, card) => valueIn(V, f, card);
+  function visible(f) {
+    return (f.show || []).every(([name, op, want]) => {
+      const have = V[name];
+      if (op === "==") return same(have, want);
+      if (op === "!=") return !same(have, want);
+      if (op === "in") return want.some((x) => same(x, have));
+      if (have == null || have === "" || isNaN(+have)) return false;
+      return op === ">" ? +have > want : +have < want;
+    });
+  }
+  function put(f, card, v, redraw) {
+    if (card == null) V[f.key] = v;
+    else V[LIST.key][card][sub(f)] = v;
+    if (f.mirror) {
+      const m = findField(f.mirror);
+      if (m && (m.choices || []).some((c) => same(c[0], v))) V[f.mirror] = v;
+    }
+    if (f.fills && f.presets && f.presets[v]) V[f.fills] = f.presets[v].value;
+    if (redraw || f.fills) redrawView(); else paint();
+    queueValidate();
+  }
+  function findField(key) {
+    for (const g of M.layout.groups) for (const p of g.parts) for (const f of p.fields) {
+      if (f.key === key) return f;
+      for (const s of f.fields || []) if (s.key === key) return s;
+    }
+    return null;
+  }
+
+  /* ---------------- numbers: stored units <-> shown units ---------------- */
+  const decimals = (x) => { const s = String(x); return s.includes(".") ? s.split(".")[1].length : 0; };
+  function shown(f, v) {
+    if (v == null || v === "") return "";
+    return String(+(Number(v) / (f.scale || 1)).toFixed(6));
+  }
+  function stored(f, x) {
+    const st = f.step || (f.type === "integer" ? 1 : 0);
+    let v = x * (f.scale || 1);
+    if (st) v = Math.round(v / st) * st;
+    if (f.min != null) v = Math.max(f.min, v);
+    if (f.max != null) v = Math.min(f.max, v);
+    return f.type === "integer" ? Math.round(v) : +v.toFixed(Math.min(10, decimals(st) + 2));
+  }
+
+  /* ---------------- controls ---------------- */
+  // A choice the page can only keep stays offered while it is the stored value.
+  function choicesOf(f, card) {
+    const cur = get(f, card), was = valueIn(ORIG, f, card);
+    const out = (f.choices || []).filter((c) => !c[2] || same(c[0], cur) || same(c[0], was));
+    if (cur != null && cur !== "" && !out.some((c) => same(c[0], cur))) out.push([cur, String(cur)]);
+    return out;
+  }
+  function toggle(f, card, lid) {
+    const on = !!get(f, card);
+    const b = h("button", { type: "button", class: "switch", role: "switch", "aria-checked": String(on), "aria-labelledby": lid });
+    const txt = h("span", { class: "swtext", "aria-hidden": "true" }, on ? W.on : W.off);
+    b.addEventListener("click", () => {
+      const n = b.getAttribute("aria-checked") !== "true";
+      b.setAttribute("aria-checked", String(n)); txt.textContent = n ? W.on : W.off;
+      put(f, card, n);
+    });
+    return h("span", { class: "swrap" }, b, txt);
+  }
+  function radios(f, card, lid, cards) {
+    const cur = get(f, card);
+    const g = h("div", { class: cards ? "choices" : "seg", role: "radiogroup", "aria-labelledby": lid });
+    const items = choicesOf(f, card);
+    const buttons = items.map(([v, label], i) => {
+      const on = same(v, cur);
+      const hint = cards && f.hints ? f.hints[v] : "";
+      const b = h("button", { type: "button", role: "radio", class: cards ? "choice" : null, "aria-checked": String(on),
+                              tabindex: on || (!items.some((c) => same(c[0], cur)) && i === 0) ? "0" : "-1" },
+        cards ? [h("span", { class: "rad", "aria-hidden": "true" }), h("span", {}, h("div", {}, label), hint ? h("div", { class: "tiny muted" }, hint) : null)] : label);
+      b.addEventListener("click", () => put(f, card, v, true));
+      b.addEventListener("keydown", (e) => {
+        const d = { ArrowRight: 1, ArrowDown: 1, ArrowLeft: -1, ArrowUp: -1 }[e.key];
+        if (!d) return;
+        e.preventDefault();
+        const j = (i + d + items.length) % items.length;
+        put(f, card, items[j][0], true);
+        const again = document.querySelector(`[data-rk="${CSS.escape(g.dataset.rk)}"] [role=radio]:nth-child(${j + 1})`);
+        if (again) again.focus();
+      });
+      return b;
+    });
+    g.dataset.rk = f.key + "|" + card;
+    g.append(...buttons);
+    return g;
+  }
+  function select(f, card, lid) {
+    const cur = get(f, card);
+    const s = h("select", { class: "sel", "aria-labelledby": lid });
+    for (const [v, label] of choicesOf(f, card)) s.append(h("option", { value: JSON.stringify(v), selected: same(v, cur) }, label));
+    for (const [v, label] of f.later || []) s.append(h("option", { value: JSON.stringify(v), disabled: true }, label));
+    s.addEventListener("change", () => put(f, card, JSON.parse(s.value), true));
+    const preset = f.presets && f.presets[cur];
+    return preset ? h("div", { class: "row" }, s, h("span", { class: "chip" }, W.region_year.replace("{year}", preset.year))) : s;
+  }
+  function slider(f, card, lid) {
+    if (f.min == null || f.max == null) return number(f, card, lid);
+    const sc = f.scale || 1;
+    const st = f.step || (f.type === "integer" ? 1 : 0.01);
+    const v = get(f, card);
+    const r = h("input", { type: "range", min: f.min, max: f.max, step: st, value: v == null ? f.min : v, "aria-labelledby": lid });
+    const n = h("input", { class: "num", type: "number", inputmode: "decimal", min: f.min / sc, max: f.max / sc, step: st / sc, value: shown(f, v), "aria-labelledby": lid });
+    r.addEventListener("input", () => { const x = stored(f, +r.value / sc); n.value = shown(f, x); put(f, card, x); });
+    n.addEventListener("change", () => {
+      if (n.value === "" || isNaN(+n.value)) { n.value = shown(f, get(f, card)); return; }
+      const x = stored(f, +n.value); r.value = x; n.value = shown(f, x); put(f, card, x);
+    });
+    return h("div", { class: "slider" }, r, n, f.unit ? h("span", { class: "unit" }, f.unit) : null);
+  }
+  function number(f, card, lid) {
+    const sc = f.scale || 1;
+    const by = FILLED[f.key];
+    const preset = by && by.presets[V[by.key]];
+    const n = h("input", { class: "num", type: "number", inputmode: "decimal", step: f.step ? f.step / sc : "any",
+                           min: f.min == null ? null : f.min / sc, max: f.max == null ? null : f.max / sc,
+                           value: shown(f, get(f, card)), disabled: !!preset, "aria-labelledby": lid });
+    n.addEventListener("input", () => {
+      if (n.value === "") { if (f.optional) put(f, card, null); return; }
+      if (!isNaN(+n.value)) put(f, card, stored(f, +n.value));
+    });
+    n.addEventListener("change", () => { n.value = shown(f, get(f, card)); });
+    return h("div", {}, h("div", { class: "row" }, n, f.unit ? h("span", { class: "unit" }, f.unit) : null),
+             preset ? h("div", { class: "tiny muted" }, W.preset.description) : null);
+  }
+  function text(f, card, lid) {
+    const v = get(f, card);
+    const t = h("input", { class: "txt", type: "text", value: v == null ? "" : v, autocapitalize: "none", spellcheck: "false", "aria-labelledby": lid });
+    t.addEventListener("input", () => put(f, card, t.value));
+    return t;
+  }
+  function locked(f, card, lid) {
+    const box = h("div", {});
+    const id = f.key + "#" + card;
+    const open = () => { UNLOCKED.add(id); box.replaceChildren(slider(f, card, lid)); };
+    if (UNLOCKED.has(id)) { open(); return box; }
+    const v = get(f, card);
+    box.append(h("div", { class: "row" },
+      h("strong", {}, v == null ? W.not_set : shown(f, v) + (f.unit ? " " + f.unit : "")),
+      h("span", { class: "chip" }, W.locked),
+      h("button", { type: "button", class: "btn link", "aria-label": W.change + ": " + f.label, onclick: open }, W.change)));
+    return box;
+  }
+
+  /* entity picker: search, the matching kind first, the live reading */
+  const ENT = {};
+  function entities(kind) {
+    const now = Date.now();
+    const e = ENT[kind];
+    if (e && now - e.at < 30000) return e.p;
+    const p = fetch("ha/entities?kind=" + encodeURIComponent(kind || ""), { cache: "no-store" })
+      .then((r) => (r.ok ? r.json() : { available: false, entities: [] }))
+      .catch(() => ({ available: false, entities: [] }));
+    ENT[kind] = { at: now, p };
+    return p;
+  }
+  const reading = (e) => (e && e.state != null && e.state !== "" ? String(e.state) + (e.unit ? " " + e.unit : "") : "–");
+  function picker(f, lid, value, pick) {
+    let data = null, all = false;
+    const btn = h("button", { type: "button", class: "ent-btn", "aria-expanded": "false", "aria-haspopup": "listbox", "aria-labelledby": lid });
+    const pop = h("div", { class: "ent-pop", hidden: true });
+    const q = h("input", { type: "search", placeholder: W.picker.search.description, "aria-label": W.picker.search.description, autocomplete: "off", spellcheck: "false" });
+    const note = h("div", { class: "tiny muted ent-note" });
+    const list = h("div", { class: "ent-list", role: "listbox", "aria-labelledby": lid });
+    const allBox = h("label", { class: "tiny muted ent-all" },
+      h("input", { type: "checkbox", onchange: (e) => { all = e.target.checked; fill(); } }), W.picker.all);
+    function drawBtn() {
+      const id = value();
+      const e = data && data.entities.find((x) => x.entity_id === id);
+      btn.replaceChildren();
+      if (id) btn.append(h("span", { class: "grow" }, h("div", {}, e ? e.name : id), h("div", { class: "key" }, id)),
+                         data && data.available ? h("span", { class: "chip " + (e ? "now" : "rs") }, e ? reading(e) : W.picker.missing) : null);
+      else btn.append(h("span", { class: "grow muted" }, W.picker.choose));
+      btn.append(h("span", { class: "muted", "aria-hidden": "true" }, "▾"));
+    }
+    function opt(id, name, val) {
+      return h("button", { type: "button", class: "ent-opt", role: "option", "aria-selected": String(id === value()),
+                           onclick: () => { pick(id); close(); drawBtn(); btn.focus(); } },
+        h("span", { class: "grow" }, h("div", {}, name), h("div", { class: "key" }, id)), val ? h("span", { class: "v" }, val) : null);
+    }
+    function fill() {
+      const typed = q.value.trim();
+      const t = typed.toLowerCase();
+      const rows = (data ? data.entities : []).filter((e) => (all || e.match) && (e.entity_id + " " + e.name).toLowerCase().includes(t)).slice(0, 200);
+      list.replaceChildren(...rows.map((e) => opt(e.entity_id, e.name, reading(e))));
+      if (typed.includes(".") && !rows.some((e) => e.entity_id === typed)) list.append(opt(typed, W.picker.use, ""));
+      if (!list.children.length) list.append(h("div", { class: "small muted", style: "padding:10px" }, W.picker.none.description));
+      note.textContent = data && data.text ? data.text : "";
+      note.hidden = !note.textContent;
+    }
+    function close() { pop.hidden = true; btn.setAttribute("aria-expanded", "false"); }
+    btn.addEventListener("click", () => {
+      if (!pop.hidden) { close(); return; }
+      pop.hidden = false; btn.setAttribute("aria-expanded", "true"); q.value = ""; fill();
+      setTimeout(() => q.focus(), 0);
+    });
+    q.addEventListener("input", fill);
+    pop.addEventListener("keydown", (e) => {
+      if (e.key === "Escape") { e.preventDefault(); close(); btn.focus(); return; }
+      if (e.key !== "ArrowDown" && e.key !== "ArrowUp") return;
+      e.preventDefault();
+      const opts = [...list.querySelectorAll(".ent-opt")];
+      const i = opts.indexOf(document.activeElement);
+      const j = e.key === "ArrowDown" ? Math.min(opts.length - 1, i + 1) : i - 1;
+      if (j < 0) q.focus(); else if (opts[j]) opts[j].focus();
+    });
+    pop.append(q, note, list, allBox);
+    drawBtn();
+    entities(f.kind).then((d) => { data = d; drawBtn(); if (!pop.hidden) fill(); });
+    return h("div", { class: "ent" }, btn, pop,
+      f.optional ? h("button", { type: "button", class: "btn link tiny", onclick: () => { pick(""); drawBtn(); } }, W.picker.clear) : null);
+  }
+  function entity(f, card, lid) {
+    return picker(f, lid, () => get(f, card) || "", (v) => put(f, card, v));
+  }
+  function entityList(f, card, lid) {
+    const arr = () => (Array.isArray(get(f, card)) ? get(f, card) : []);
+    const box = h("div", { class: "elist" });
+    arr().forEach((_id, i) => {
+      box.append(h("div", { class: "erow" },
+        h("div", { class: "tiny muted" }, W.phase + " " + (i + 1)),
+        picker(f, lid, () => arr()[i] || "", (v) => { const a = arr().slice(); a[i] = v; put(f, card, a); }),
+        h("button", { type: "button", class: "btn link tiny", onclick: () => { const a = arr().slice(); a.splice(i, 1); put(f, card, a, true); } }, W.remove)));
+    });
+    box.append(h("button", { type: "button", class: "btn", onclick: () => put(f, card, arr().concat([""]), true) }, "+ " + W.add_row));
+    return box;
+  }
+  function solarList(f, card, lid) {
+    const arr = () => (Array.isArray(get(f, card)) ? get(f, card) : []);
+    const box = h("div", { class: "elist" });
+    arr().forEach((row, i) => {
+      const flip = h("button", { type: "button", class: "switch", role: "switch", "aria-checked": String(!!row.reversed), "aria-label": W.reversed });
+      flip.addEventListener("click", () => { const a = clone(arr()); a[i].reversed = !a[i].reversed; put(f, card, a, true); });
+      box.append(h("div", { class: "erow" },
+        picker(f, lid, () => arr()[i].entity || "", (v) => { const a = clone(arr()); a[i].entity = v; put(f, card, a); }),
+        h("div", { class: "row" }, h("span", { class: "swrap" }, flip, h("span", { class: "swtext" }, W.reversed)),
+          h("button", { type: "button", class: "btn link tiny", onclick: () => { const a = clone(arr()); a.splice(i, 1); put(f, card, a, true); } }, W.remove))));
+    });
+    box.append(h("button", { type: "button", class: "btn", onclick: () => put(f, card, arr().concat([{ entity: "", reversed: false }]), true) }, "+ " + W.add_solar));
+    return box;
+  }
+  const CONTROLS = { toggle, segmented: (f, c, l) => radios(f, c, l, false), choice: (f, c, l) => radios(f, c, l, true),
+                     select, slider, number, text, locked, entity, entity_list: entityList, solar_list: solarList };
+
+  /* ---------------- rows, cards and groups ---------------- */
+  function keyText(f, card) {
+    if (view === "setup") return "";     // the wizard shows no keys
+    if (card != null) return V[LIST.shape] === "flat" && f.flat ? f.flat : LIST.key + "[" + card + "]." + sub(f);
+    return f.key.startsWith("ui.") ? (f.writes || []).join(", ") : f.key;
+  }
+  function fieldRow(f, card, gid) {
+    if (f.control === "inverter_list") return cardList(f, gid);
+    const lid = "sf" + (++uid);
+    const keys = keyText(f, card);
+    const msg = h("div", { class: "msgs" });
+    const make = CONTROLS[f.control] || text;
+    const row = h("div", { class: "f" + (f.control === "toggle" ? " inline" : ""), "data-key": f.key, "data-card": card },
+      h("div", { class: "head" }, h("div", { class: "lbl", id: lid }, f.label, f.unit && f.control !== "slider" && f.control !== "number" && f.control !== "locked" ? " (" + f.unit + ")" : ""),
+        keys ? h("div", { class: "key" }, keys) : null),
+      h("div", { class: "ctl" }, make(f, card, lid)),
+      f.help ? h("div", { class: "help" }, f.help) : null, msg);
+    ROWS.push({ f, card, el: row, msg, gid, search: (f.label + " " + keys + " " + f.key + " " + (f.help || "")).toLowerCase() });
+    return row;
+  }
+  function blankCard(f, first) {
+    const out = {};
+    for (const s of f.fields) {
+      const k = sub(s);
+      out[k] = s.control === "slider" && first && first[k] != null ? first[k] : s.type === "boolean" ? false : s.control === "number" ? null : "";
+    }
+    return out;
+  }
+  function cardList(f, gid) {
+    const wrap = h("div", { class: "invs", "data-key": f.key });
+    const msg = h("div", { class: "msgs" });
+    const cards = V[f.key];
+    if (!Array.isArray(cards)) {
+      wrap.append(h("div", { class: "msg info" }, W.raw_roster.description), msg);
+    } else {
+      cards.forEach((c, i) => {
+        const box = h("div", { class: "inv" }, h("div", { class: "hd" },
+          h("span", { class: "grow" }, c.name || W.inverter + " " + (i + 1)), view === "setup" ? null : h("span", { class: "key" }, f.key + "[" + i + "]"),
+          cards.length > 1 ? h("button", { type: "button", class: "btn link tiny", onclick: () => {
+            V[f.key].splice(i, 1); V[f.count] = V[f.key].length;
+            // Back to one card, the stored shape returns: a flat inverter stays flat.
+            if (V[f.key].length === 1) for (const k in f.grow) V[k] = clone(ORIG[k]);
+            put(f, null, V[f.key], true);
+          } }, W.remove) : null));
+        for (const s of f.fields) box.append(fieldRow(s, i, gid));
+        wrap.append(box);
+      });
+      wrap.append(msg, h("button", { type: "button", class: "btn", onclick: () => {
+        V[f.key].push(blankCard(f, V[f.key][0])); Object.assign(V, f.grow); V[f.count] = V[f.key].length;
+        put(f, null, V[f.key], true);
+      } }, "+ " + W.add_inverter));
+    }
+    ROWS.push({ f, card: null, el: wrap, msg, gid, list: true, search: (f.label + " " + f.key + " " + (f.help || "")).toLowerCase() });
+    return wrap;
+  }
+  const chev = () => h("span", { class: "chev", "aria-hidden": "true" }, "›");
+  function render() {
+    const host = $("#groups");
+    const y = window.scrollY;
+    host.replaceChildren();
+    ROWS.length = 0;
+    for (const g of M.layout.groups) {
+      const d = h("details", { class: "grp", "data-g": g.id },
+        h("summary", {}, h("span", { class: "grow" }, h("strong", {}, g.name), h("span", { class: "small muted gdesc" }, g.description)),
+          h("span", { class: "gchips" }, h("span", { class: "gbadge" }), ...g.applies.map((a) => h("span", { class: "chip applies" }, a))), chev()));
+      d.open = OPEN.has(g.id);
+      d.addEventListener("toggle", () => { if (!$("#set-search").value) (d.open ? OPEN.add(g.id) : OPEN.delete(g.id)); });
+      const body = h("div", { class: "body" });
+      if (g.support_only) body.append(h("div", { class: "msg warn", role: "note" }, W.support.description));
+      for (const p of g.parts) {
+        const pid = g.id + "." + p.id;
+        let box;
+        if (p.collapsed) {
+          box = h("details", { class: "sub part" }, h("summary", {}, p.name));
+          box.open = OPEN.has(pid);
+          box.addEventListener("toggle", () => { if (!$("#set-search").value) (box.open ? OPEN.add(pid) : OPEN.delete(pid)); });
+        } else {
+          box = h("div", { class: "part" }, p.name ? h("div", { class: "subhead" }, p.name) : null);
+        }
+        if (p.description) box.append(h("p", { class: "small muted", style: "margin:4px 0" }, p.description));
+        for (const f of p.fields) box.append(fieldRow(f, null, g.id));
+        body.append(box);
+      }
+      if (g.id === "maintenance") {
+        body.append(h("div", { class: "part" }, h("div", { class: "subhead" }, W.cycle.name),
+          h("p", { class: "small muted", style: "margin:4px 0" }, W.cycle.description),
+          h("div", { class: "row" },
+            h("button", { type: "button", class: "btn", onclick: () => maint("maint_start") }, ROOT.home.control.maint_start),
+            h("button", { type: "button", class: "btn danger", onclick: () => maint("maint_abort") }, ROOT.home.control.maint_abort))));
+      }
+      d.append(body);
+      host.append(d);
+    }
+    paint();
+    window.scrollTo(0, y);
+  }
+
+  /* ---------------- messages, visibility, search, badges ---------------- */
+  const ICON = { bad: "×", warn: "!", info: "i" };
+  const RANK = { bad: 0, warn: 1, info: 2 };
+  function mine(r, m) {
+    if (m.field !== r.f.key) return false;
+    if (r.list || r.card == null) return true;
+    return m.card == null ? r.card === 0 : m.card === r.card;
+  }
+  function paint() {
+    const q = view === "setup" ? "" : $("#set-search").value.trim().toLowerCase();
+    const placed = new Set();
+    for (const r of ROWS) {
+      r.visible = visible(r.f);
+      const msgs = MSG.filter((m, i) => { const hit = mine(r, m); if (hit && r.visible) placed.add(i); return hit; })
+        .sort((a, z) => RANK[a.tier] - RANK[z.tier]);
+      r.tiers = new Set(msgs.map((m) => m.tier));
+      r.msg.replaceChildren(...msgs.map((m) => h("div", { class: "msg " + m.tier },
+        h("span", { class: "mi", "aria-hidden": "true" }, ICON[m.tier] || "i"),
+        h("span", {}, h("span", { class: "sr" }, W.tier[m.tier] + ": "), m.text))));
+      r.el.classList.toggle("has-bad", r.tiers.has("bad"));
+      // A card list counts as one change when cards were added or removed;
+      // an edit inside a card counts on its own row.
+      r.changed = r.list ? !same((get(r.f) || []).length, (valueIn(ORIG, r.f) || []).length)
+                         : !same(get(r.f, r.card), valueIn(ORIG, r.f, r.card));
+      r.el.classList.toggle("changed", r.changed && !r.list);
+    }
+    // Search: a row shows when it is visible and matches. A card list shows
+    // while any of its rows does.
+    for (const r of ROWS) if (!r.list) r.el.hidden = !(r.visible && (!q || r.search.includes(q)));
+    for (const r of ROWS) if (r.list) r.el.hidden = !!q && !r.search.includes(q) && !ROWS.some((s) => !s.list && s.card != null && !s.el.hidden);
+    let any = false;
+    document.querySelectorAll("#groups details.grp").forEach((d) => {
+      const rows = ROWS.filter((r) => r.gid === d.dataset.g);
+      d.querySelectorAll(".part").forEach((p) => {
+        const inside = rows.filter((r) => p.contains(r.el));
+        if (inside.length) p.hidden = inside.every((r) => r.el.hidden);
+      });
+      const hit = rows.some((r) => !r.el.hidden);
+      any = any || hit;
+      d.hidden = !!q && !hit;
+      if (q && hit) { d.open = true; d.querySelectorAll("details.sub").forEach((s) => { s.open = true; }); }
+      const shownRows = rows.filter((r) => r.visible && !r.list);
+      const bad = shownRows.filter((r) => r.tiers.has("bad")).length + rows.filter((r) => r.list && r.tiers.has("bad")).length;
+      const warn = shownRows.filter((r) => !r.tiers.has("bad") && r.tiers.has("warn")).length;
+      const changed = rows.filter((r) => r.changed).length;
+      d.querySelector(".gbadge").replaceChildren(...[
+        bad ? h("span", { class: "chip bad" }, bad + " " + W.to_fix) : null,
+        warn ? h("span", { class: "chip rs" }, warn + " " + W.to_check) : null,
+        changed ? h("span", { class: "chip changed" }, changed + " " + W.changed) : null].filter(Boolean));
+    });
+    $("#set-nomatch").hidden = !q || any;
+    // A sentence shown beside any field is not repeated here.
+    const shownText = new Set(MSG.filter((m, i) => placed.has(i)).map((m) => m.text));
+    const other = MSG.filter((m, i) => !shownText.has(m.text) && MSG.findIndex((x) => x.text === m.text) === i);
+    if (DEVICE) other.push({ tier: "info", text: DEVICE });
+    $("#set-other").hidden = !other.length;
+    $("#set-other-list").replaceChildren(...other.map((m) => h("li", { class: "c-" + ({ bad: "bad", warn: "warn" }[m.tier] || "info") },
+      h("span", { class: "sr" }, W.tier[m.tier] + ": "), (ICON[m.tier] || "i") + " " + m.text)));
+    savebar();
+  }
+  function dirtyCount() {
+    const seen = new Set();
+    for (const r of ROWS) if (r.changed) seen.add(r.f.key + "#" + r.card);
+    return seen.size;
+  }
+  function savebar() {
+    const n = V ? dirtyCount() : 0;
+    $("#savebar").hidden = !(view === "settings" && n);
+    $("#sb-text").textContent = n + " " + (n === 1 ? W.savebar.one : W.savebar.many);
+  }
+  $("#set-search").addEventListener("input", () => { if (V) paint(); });
+
+  /* ---------------- talking to the add-on ---------------- */
+  let vtimer = null, vseq = 0;
+  function queueValidate() { clearTimeout(vtimer); vtimer = setTimeout(validate, 400); }
+  // `extra` asks for more, e.g. the wizard's live checks. Returns the answer,
+  // or null when it failed or a newer check overtook it.
+  async function validate(extra) {
+    const seq = ++vseq;
+    try {
+      const r = await fetch("config/validate", { method: "POST", headers: { "Content-Type": "application/json" },
+                                                 body: JSON.stringify(Object.assign({ model: V }, extra || {})) });
+      const b = await r.json();
+      if (seq !== vseq) return null;
+      MSG = b.messages || [];
+      DEVICE = b.device_note || "";
+      STEPS = b.steps || {};
+      paint();
+      return b;
+    } catch (e) { return null; /* the next change tries again */ }
+  }
+  function banner(level, title, sub, button, onClick) {
+    const host = $("#set-banner");
+    if (!title) { host.replaceChildren(); return; }
+    host.replaceChildren(h("div", { class: "banner " + ({ ok: "b-ok", bad: "b-bad" }[level] || "b-warn") },
+      h("span", { class: "ic", "aria-hidden": "true" }, { ok: "✓", bad: "×" }[level] || "!"),
+      h("span", {}, title, h("small", {}, sub, button ? [" ", h("button", { type: "button", class: "btn link", onclick: onClick }, button)] : null))));
+  }
+  function restart() {
+    ask(W.dialog, async () => {
+      try {
+        await fetch("config/restart", { method: "POST", headers: { "Content-Type": "application/json" },
+                                        body: JSON.stringify({ confirm: "restart" }) });
+      } catch (e) { /* the add-on stops answering while it restarts */ }
+      toast(W.toast.restarting.description);
+    });
+  }
+  async function load(after) {
+    let m;
+    try {
+      const r = await fetch("config/model?lang=en", { cache: "no-store" });
+      if (!r.ok) throw new Error("model " + r.status);
+      m = await r.json();
+      if (!m.layout || !m.ui) throw new Error("no layout");
+    } catch (e) {
+      $("#groups").replaceChildren();
+      $("#set-search").hidden = true;
+      banner("bad", W.load_failed.name, W.load_failed.description);
+      return;
+    }
+    M = m; V = clone(m.ui); ORIG = clone(m.ui); FP = m.fingerprint; MSG = []; DEVICE = "";
+    UNLOCKED.clear();
+    $("#set-search").hidden = false;
+    FILLED = {};
+    LIST = null;
+    for (const g of M.layout.groups) for (const p of g.parts) for (const f of p.fields) {
+      if (f.fills) FILLED[f.fills] = f;
+      if (f.control === "inverter_list") LIST = f;
+    }
+    if (!OPEN.size && M.layout.groups.length) OPEN.add(M.layout.groups[0].id);
+    if (after === "saved") banner("ok", W.saved.name, W.saved.description, W.restart, restart);
+    else if ((m.running_differs || []).length) banner("warn", W.differs.name, W.differs.description, W.restart, restart);
+    else banner();
+    if (view === "setup") drawStep(); else render();
+    validate();
+  }
+  function firstBad() {
+    const r = ROWS.find((x) => x.tiers && x.tiers.has("bad") && x.visible);
+    if (!r) { if (!$("#set-other").hidden) $("#set-other").scrollIntoView({ block: "center" }); return; }
+    for (let p = r.el.parentElement; p; p = p.parentElement) if (p.tagName === "DETAILS") p.open = true;
+    r.el.scrollIntoView({ block: "center" });
+    const input = r.el.querySelector("input,select,button");
+    if (input) input.focus({ preventScroll: true });
+  }
+  // The one save path, for the Installer view and the wizard. After a stale
+  // refusal the page holds the new token, so a second press saves.
+  async function postSave(extra) {
+    const r = await fetch("config/save", { method: "POST", headers: { "Content-Type": "application/json" },
+                                           body: JSON.stringify(Object.assign({ model: V, fingerprint: FP }, extra || {})) });
+    const b = await r.json().catch(() => ({}));
+    if (r.status === 409 && b.kind === "stale") FP = b.fingerprint || FP;
+    return { r, b };
+  }
+  // The settings another surface changed (not this page's own edits).
+  function staleText(b) {
+    const names = (b.changed_fields || []).map((k) => { const f = findField(k); return f ? f.label : k; });
+    return W.stale.description + (names.length ? " " + names.join(", ") + "." : "");
+  }
+  async function save() {
+    const btn = $("#sb-save");
+    btn.disabled = true; btn.textContent = W.savebar.saving;
+    try {
+      clearTimeout(vtimer);
+      await validate();
+      if (MSG.some((m) => m.tier === "bad")) { toast(W.toast.blocked.description); firstBad(); return; }
+      const { r, b } = await postSave();
+      if (r.ok) { toast(W.toast.saved); await load("saved"); return; }
+      if (r.status === 409 && b.kind === "stale") {
+        banner("bad", W.stale.name, staleText(b));
+        return;
+      }
+      if (r.status === 422) { MSG = b.messages || []; paint(); toast(W.toast.blocked.description); firstBad(); return; }
+      toast(W.toast.failed);
+    } catch (e) { toast(W.toast.failed); }
+    finally { btn.disabled = false; btn.textContent = W.savebar.save; }
+  }
+  $("#sb-save").addEventListener("click", save);
+  // Discard reloads what is stored: after a stale save ORIG is no longer it.
+  $("#sb-discard").addEventListener("click", async () => {
+    await load(); toast(W.toast.discarded);
+  });
+  addEventListener("beforeunload", (e) => { if (V && dirtyCount()) { e.preventDefault(); e.returnValue = ""; } });
+
+  /* ---------------- the setup wizard (P4) ---------------- */
+  const WS = W.setup;
+  const WZ = { step: 1, kettle: null, shadowOn: true, done: "", checked: null };
+  function redrawView() { if (view === "setup") drawStep(); else render(); }
+  function allFields() {
+    const out = [];
+    for (const g of M.layout.groups) for (const p of g.parts) for (const f of p.fields) out.push(f);
+    return out;
+  }
+  const say = (text, vars) => Object.keys(vars || {}).reduce((t, k) => t.replace("{" + k + "}", vars[k]), text);
+  function watts(w, signed) {
+    const n = String(Math.round(Math.abs(w))).replace(/\B(?=(\d{3})+(?!\d))/g, " ");
+    return (signed && w < 0 ? "-" : "") + n + " W";
+  }
+  function line(tier, text) {
+    const icon = { ok: "✓", bad: "×", warn: "!", info: "i" }[tier] || "i";
+    return h("li", {}, h("span", { class: "sev " + tier, "aria-hidden": "true" }, icon),
+      h("span", {}, h("span", { class: "sr" }, (W.tier[tier] || "") + ": "), text));
+  }
+
+  // Step 1's kettle test. The table is app/uilayout.py's KETTLE; this is
+  // uipage.kettle() (test_setup.py grades that one) on the page.
+  function kettleSource() { const K = M.setup.kettle; return K.sources[V[K.source]] || null; }
+  function kettleSig(src) { return JSON.stringify([V[M.setup.kettle.source], src.read.map(([k]) => V[k] || "")]); }
+  function kettleOutcome(src, before, after) {
+    const d = after - before;
+    if (Math.abs(d) < M.setup.kettle.min_w) return { say: "none", sets: null, d };
+    const o = src[d > 0 ? "up" : "down"];
+    return { say: o.say, sets: o.sets, d };
+  }
+  function kettleOk() {
+    const src = kettleSource();
+    return !src || !!(WZ.kettle && WZ.kettle.sig === kettleSig(src) && WZ.kettle.ok);
+  }
+  async function readMeter(src) {
+    let total = 0;
+    for (const [key, sign] of src.read) {
+      if (!V[key]) return null;
+      const r = await fetch("ha/entities?entity=" + encodeURIComponent(V[key]), { cache: "no-store" })
+        .then((x) => (x.ok ? x.json() : null)).catch(() => null);
+      if (!r || r.watts == null) return null;
+      total += sign * r.watts;
+    }
+    return total;
+  }
+  function kettleBox() {
+    const src = kettleSource();
+    const box = h("div", { class: "f kettle" }, h("div", { class: "lbl" }, WS.kettle.name));
+    if (!src) { box.append(h("div", { class: "help" }, WS.kettle.self.description)); return box; }
+    const sig = kettleSig(src);
+    if (WZ.kettle && WZ.kettle.sig !== sig) WZ.kettle = null;     // another meter: test again
+    const k = WZ.kettle || { sig };
+    box.append(h("div", { class: "help" }, WS.kettle.description));
+    const tone = { ok: "ok", flip: "info", none: "warn", unread: "bad", skipped: "warn" }[k.say] || "bad";
+    const words = k.say ? WS.kettle[k.say] : k.before != null ? WS.kettle.before : null;
+    if (words) box.append(h("div", { class: "msg " + (k.say ? tone : "info"), role: "status" },
+      say(words.description, { w: k.before != null ? watts(k.before, true) : "", d: k.d != null ? watts(k.d) : "" })));
+    const busy = (b) => { b.disabled = true; };
+    const read = h("button", { type: "button", class: "btn" }, k.before != null && !k.ok ? WS.kettle.again : WS.kettle.read);
+    read.addEventListener("click", async () => {
+      busy(read);
+      const sig = kettleSig(src);           // the entity may have changed since drawing
+      if (k.sig !== sig) { k.before = null; k.ok = false; k.sig = sig; }
+      const w = await readMeter(src);
+      if (w == null) WZ.kettle = Object.assign({}, k, { sig, say: "unread" });
+      else if (k.before == null || k.ok) WZ.kettle = { sig, before: w, wrong: !k.ok && !!k.wrong };
+      else {
+        const o = kettleOutcome(src, k.before, w);
+        // `wrong`: the reading went the way no option can fix. A skip after
+        // that keeps saying so on the last step (review R2).
+        const wrong = o.say === "none" ? !!k.wrong : o.sets == null;
+        WZ.kettle = { sig, before: o.say === "none" ? k.before : null, say: o.say, d: o.d, ok: o.sets != null, wrong };
+        if (o.sets) { Object.assign(V, o.sets); queueValidate(); }
+      }
+      drawStep();
+    });
+    const row = h("div", { class: "row" }, read);
+    if (!k.ok) row.append(h("button", { type: "button", class: "btn link", onclick: () => {
+      WZ.kettle = { sig: kettleSig(src), say: "skipped", ok: true, skipped: true, wrong: !!k.wrong }; drawStep();
+    } }, WS.kettle.skip));
+    box.append(row);
+    return box;
+  }
+
+  // Step 6: the shadow switch, the checks, and Save and restart.
+  // The shadow switch goes only on the model the wizard posts, never into V,
+  // which the Installer view saves too (review R3).
+  function shadowValue() {
+    const s = M.setup.shadow;
+    return WZ.shadowOn ? s.on : (ORIG[s.field] !== s.on ? ORIG[s.field] : s.off);
+  }
+  function posted() { return Object.assign({}, V, { [M.setup.shadow.field]: shadowValue() }); }
+  function shadowRow() {
+    const lid = "wzs";
+    const b = h("button", { type: "button", class: "switch", role: "switch", "aria-checked": String(WZ.shadowOn), "aria-labelledby": lid });
+    b.addEventListener("click", () => { WZ.shadowOn = !WZ.shadowOn; drawStep(); });
+    return h("div", { class: "f inline" },
+      h("div", {}, h("div", { class: "lbl", id: lid }, WS.shadow.name), h("div", { class: "help" }, WS.shadow.description)),
+      h("div", { class: "ctl" }, b));
+  }
+  async function runChecks() {
+    const list = $("#wz-checks");
+    if (list) list.replaceChildren(line("info", WS.check.running.description));
+    clearTimeout(vtimer);
+    const b = await validate({ setup: true, model: posted() });
+    WZ.checked = b;
+    if (!list || !list.isConnected) return b;
+    if (!b) { list.replaceChildren(line("bad", WS.check.failed.description)); return b; }
+    const items = [], seen = new Set();
+    const add = (tier, text) => { if (!seen.has(text)) { seen.add(text); items.push([tier, text]); } };
+    const bad = (b.messages || []).filter((m) => m.tier === "bad");
+    if (!bad.length) add("ok", WS.check.pass.description);
+    for (const m of bad) add("bad", m.text);
+    for (const m of b.setup || []) add(m.tier, m.text);
+    if (b.device_note) add("info", b.device_note);
+    const src = kettleSource();
+    if (!src) add("info", WS.kettle.self.description);
+    else if (WZ.kettle && WZ.kettle.skipped) add("warn", (WZ.kettle.wrong ? WS.kettle.skipped_wrong : WS.kettle.skipped).description);
+    else if (kettleOk()) add("ok", WS.kettle.tested.description);
+    const rank = { bad: 0, warn: 1, ok: 2, info: 3 };
+    items.sort((a, z) => rank[a[0]] - rank[z[0]]);
+    list.replaceChildren(...items.map(([t, x]) => line(t, x)));
+    WZ.blocked = items.some(([t]) => t === "bad");
+    return b;
+  }
+  function finalBox() {
+    const again = h("button", { type: "button", class: "btn", onclick: runChecks }, WS.check.again);
+    setTimeout(runChecks, 0);
+    return [h("div", { class: "subhead" }, WS.check.name),
+      h("ul", { class: "plain checklist small", id: "wz-checks", "aria-live": "polite" }), h("div", { class: "row" }, again),
+      shadowRow()];
+  }
+  function wzBanner(level, title, sub, button, onClick) {
+    const host = $("#wz-banner");
+    if (!title) { host.replaceChildren(); return; }
+    host.replaceChildren(h("div", { class: "banner " + ({ ok: "b-ok", bad: "b-bad" }[level] || "b-warn") },
+      h("span", { class: "ic", "aria-hidden": "true" }, { ok: "✓", bad: "×" }[level] || "!"),
+      h("span", {}, title, h("small", {}, sub, button ? [" ", h("button", { type: "button", class: "btn link", onclick: onClick }, button)] : null))));
+  }
+  async function finish() {
+    const b = await runChecks();
+    if (!b) { toast(WS.check.failed.description); return; }
+    if (WZ.blocked) { toast(WS.check.blocked.description); return; }
+    const shadow = shadowValue() === M.setup.shadow.on;
+    ask(shadow ? WS.dialog : WS.dialog_live, async () => {
+      wzBanner();
+      let res;
+      try { res = await postSave({ setup: "done", model: posted() }); } catch (e) { toast(W.toast.failed); return; }
+      const { r, b: body } = res;
+      if (r.status === 409 && body.kind === "stale") { wzBanner("bad", W.stale.name, staleText(body)); return; }
+      if (r.status === 422) {
+        MSG = body.messages || []; STEPS = body.steps || {};
+        const first = Object.keys(STEPS).map(Number).sort((a, z) => a - z).find((n) => STEPS[n] > 0);
+        if (first) WZ.step = first;
+        drawStep(); toast(W.toast.blocked.description); firstBad();
+        return;
+      }
+      if (!r.ok) { toast(W.toast.failed); return; }
+      let restarted = true;
+      try {
+        const rr = await fetch("config/restart", { method: "POST", headers: { "Content-Type": "application/json" },
+                                                   body: JSON.stringify({ confirm: "restart" }) });
+        restarted = rr.ok;
+      } catch (e) { /* the add-on stops answering while it restarts */ }
+      WZ.done = restarted ? (shadow ? "done" : "done_live") : "restart_failed";
+      drawStep();
+      if (!restarted) await load("saved");      // still running: read what is stored
+    });
+  }
+  function drawDone() {
+    const w = WS[WZ.done];
+    $("#wz-count").textContent = "";
+    $("#wz-steps").replaceChildren();
+    $("#wz-desc").textContent = "";
+    $("#wz-nav").hidden = true;
+    ROWS.length = 0;
+    if (WZ.done === "restart_failed") wzBanner("warn", w.name, w.description, W.restart, restart);
+    else wzBanner("ok", w.name, w.description);
+    $("#wz-body").replaceChildren(h("a", { class: "btn primary", href: "#home" }, WS.home));
+  }
+  function drawStep() {
+    if (!M) return;
+    if (WZ.done) { drawDone(); return; }
+    const S = M.setup, n = WZ.step, words = WS.steps[n];
+    $("#wz-nav").hidden = false;
+    $("#wz-title").textContent = words.name;
+    $("#wz-count").textContent = say(WS.step, { n, total: S.steps });
+    $("#wz-steps").replaceChildren(...Array.from({ length: S.steps }, (_x, i) =>
+      h("i", { class: i + 1 < n ? "done" : i + 1 === n ? "cur" : null })));
+    $("#wz-desc").textContent = words.description;
+    ROWS.length = 0;
+    const body = [];
+    if (n === 1 && !M.setup_needed) body.push(h("div", { class: "msg info" }, WS.done_before.description));
+    for (const f of allFields()) if (f.wizard === n && f.key !== S.shadow.field) body.push(fieldRow(f, null, "wz"));
+    if (n === 1) body.push(kettleBox());
+    if (n === 5) body.push(h("p", { class: "small muted" }, WS.modes_later.description));
+    if (n === S.final) body.push(...finalBox());
+    $("#wz-body").replaceChildren(...body);
+    $("#wz-back").textContent = n === 1 ? WS.not_now : WS.back;
+    $("#wz-next").textContent = n === S.final ? WS.finish : S.optional.includes(n) ? WS.skip : WS.next;
+    paint();
+  }
+  $("#wz-back").addEventListener("click", () => {
+    if (WZ.step === 1) { location.hash = "#home"; return; }
+    WZ.step -= 1; drawStep(); window.scrollTo(0, 0);
+  });
+  $("#wz-next").addEventListener("click", async () => {
+    if (!M) return;
+    const btn = $("#wz-next");
+    btn.disabled = true;
+    try {
+      const n = WZ.step;
+      if (n === M.setup.final) { await finish(); return; }
+      clearTimeout(vtimer);
+      const b = await validate();
+      if (!b) { toast(W.toast.failed); return; }
+      if (n === 1 && !kettleOk()) { toast(WS.kettle.needed.description); return; }
+      if ((STEPS[n] || 0) > 0) { toast(W.toast.blocked.description); firstBad(); return; }
+      WZ.step = n + 1; drawStep(); window.scrollTo(0, 0);
+    } finally { btn.disabled = false; }
+  });
+
+  document.addEventListener("ux13:tab", (e) => {
+    view = e.detail === "settings" || e.detail === "setup" ? e.detail : null;
+    if (view && !M) load(); else if (view) { redrawView(); validate(); } else savebar();
+  });
+  // app.js chose the first tab before this file ran.
+  const sel = document.querySelector(".tab[aria-selected=true]");
+  if (sel && (sel.dataset.hash === "settings" || sel.dataset.hash === "setup")) { view = sel.dataset.hash; load(); }
+  // First run: opened with no route, on a site the add-on says is new
+  // (uipage.setup_needed), the page goes to Setup by itself.
+  else if (window.UX13.first) {
+    load().then(() => { if (M && M.setup_needed && location.hash === "#home") location.hash = "#setup"; });
+  }
+})();

goodwe_controller/app/static_tariff.py

@@ -204,6 +204,7 @@ import math
 from dataclasses import dataclass
 from datetime import datetime, timedelta, timezone
 
+from . import messages
 from .price import (
     MAX_PLAUSIBLE_EUR_KWH, Absence, PricePoint, PriceProduct, PriceRead,
     Uncertainty, _Outcome, brussels, load_prices, price_option,
@@ -222,6 +223,12 @@ _DAY_ALIASES = {
 
 MINUTES_PER_DAY = 1440
 
+# TARIFF-17. The option key whose value is a period table of the TAXES
+# component. One spelling, here, because price.py, validate.py and config.yaml
+# all name it and `provider_id()`'s note says what three spellings of one
+# decision cost.
+TAXES_PROFILE_OPTION = "price_taxes_profile"
+
 # The mean that `cheap_now()` grades against is taken over this many local days.
 # Seven, so each weekday appears exactly once - see the module docstring. It is
 # a MODULE CONSTANT and not an option on purpose: CFG-03 already tracks three
@@ -256,9 +263,8 @@ def _minutes(value, field: str) -> int:
     parts = text.split(":")
     if len(parts) != 2:
         raise ProfileInvalid(
-            f"{field} is {value!r}; it must be \"HH:MM\" local Belgian time, "
-            f"e.g. \"22:00\". A bare hour or a decimal is refused rather than "
-            f"guessed at - 7.5 could be 07:30 or 07:50.")
+            f"{field} is {value!r}. Write it as \"HH:MM\" in Belgian time, "
+            f"for example \"22:00\".")
     try:
         h, m = int(parts[0]), int(parts[1])
     except ValueError:
@@ -266,9 +272,8 @@ def _minutes(value, field: str) -> int:
                              f"integers, e.g. \"07:00\"")
     if not (0 <= m < 60) or not (0 <= h <= 24) or (h == 24 and m != 0):
         raise ProfileInvalid(
-            f"{field} is {value!r}, which is not a time of day. Hours run 0-23, "
-            f"minutes 0-59; \"24:00\" is accepted only as an END meaning "
-            f"midnight at the end of the day.")
+            f"{field} is {value!r}, which is not a time of day. Use 00:00 to "
+            f"23:59, or \"24:00\" as an end time.")
     return h * 60 + m
 
 
@@ -280,11 +285,8 @@ def _days(value, field: str) -> frozenset:
     """
     if value is None:
         raise ProfileInvalid(
-            f"{field} is missing. Name the days this period applies to - "
-            f"\"mon-fri\", \"sat,sun\" or \"all\". It is required rather than "
-            f"defaulted to every day, because a Belgian night tariff that "
-            f"silently covered the weekend too would misprice 48 h a week with "
-            f"nothing reporting it.")
+            f"{field} is missing. Name the days, for example \"mon-fri\", "
+            f"\"sat,sun\" or \"all\".")
     tokens = []
     if isinstance(value, (list, tuple)):
         for item in value:
@@ -320,13 +322,37 @@ def _days(value, field: str) -> frozenset:
     return frozenset(out)
 
 
-def _price(value, field: str) -> float:
-    """The all-in EUR/kWh for a period, bounded exactly as price.py bounds a feed."""
+# What a period's `eur_per_kwh` MEANS, per option. The grammar is one grammar
+# (TARIFF-17); the quantity it carries is not, so the "you left this out"
+# sentence is the one thing the two tables do not share.
+_PERIOD_MEANS = {
+    "static_profile":
+        "an all-in eur_per_kwh (energy + supplier markup + taxes, §9.3) - the "
+        "same basis the dynamic providers are assembled onto, so the two are "
+        "comparable",
+}
+_TAXES_MEANS = (
+    "the TAXES component alone in eur_per_kwh - the non-energy part of the "
+    "bill for that band (distribution, levies, VAT), NOT an all-in price. The "
+    "framework adds it to what the feed publishes, exactly as the scalar "
+    "price_taxes_eur_kwh is added"
+)
+_PERIOD_MEANS[TAXES_PROFILE_OPTION] = _TAXES_MEANS
+
+
+def _price(value, field: str, means: str = None) -> float:
+    """One period's EUR/kWh, bounded exactly as price.py bounds a feed.
+
+    `means` names the quantity for the error sentence only. TARIFF-17: the same
+    grammar carries an ALL-IN price under `static_profile` and a TAXES-ONLY
+    component under `price_taxes_profile`, and an operator who confuses the two
+    is out by an energy price - so the refusal says which one is wanted.
+    """
+    if means is None:
+        means = _PERIOD_MEANS["static_profile"]
     if value is None:
         raise ProfileInvalid(
-            f"{field} is missing. Every period needs an all-in eur_per_kwh "
-            f"(energy + supplier markup + taxes, §9.3) - the same basis the "
-            f"dynamic providers are assembled onto, so the two are comparable.")
+            f"{field} is missing. Every period needs {means}.")
     if isinstance(value, bool) or not isinstance(value, (int, float, str)):
         raise ProfileInvalid(f"{field} is {value!r}, which is not a number")
     try:
@@ -337,10 +363,8 @@ def _price(value, field: str) -> float:
         raise ProfileInvalid(f"{field} is {value!r}, which is not finite")
     if abs(out) > MAX_PLAUSIBLE_EUR_KWH:
         raise ProfileInvalid(
-            f"{field} is {out} EUR/kWh, beyond +-{MAX_PLAUSIBLE_EUR_KWH}. The "
-            f"usual cause is a figure in cents or in EUR/MWh - 34 instead of "
-            f"0.34 - which would make every hour look like an emergency. Same "
-            f"bound the fetched feeds are held to (price.py `_validate_raw`).")
+            f"{field} is {out} EUR/kWh, beyond +-{MAX_PLAUSIBLE_EUR_KWH}. "
+            f"Write the price in EUR/kWh, for example 0.34 and not 34.")
     return out
 
 
@@ -383,14 +407,18 @@ class Period:
 class StaticProfile:
     """A validated two-or-more-period tariff. Immutable, pure, I/O-free."""
 
-    def __init__(self, periods):
+    def __init__(self, periods, *, option: str = "static_profile"):
         self.periods = tuple(periods)
+        # ⚠️ TARIFF-17: the OPTION NAME travels with the profile so that every
+        # refusal names the key the operator actually typed. It is a default
+        # argument on purpose - every pre-existing call site and every
+        # pre-existing sentence is byte-identical without it.
+        self.option = option
         if not self.periods:
             raise ProfileInvalid(
-                "static_profile has no periods. A profile with no periods is "
-                "not a fixed tariff, it is an absent one - leave the option "
-                "empty to say that on purpose (§11.4 then applies).")
-        _check_tiling(self.periods)
+                f"{option} has no periods. Add at least one, or leave the "
+                f"setting empty.")
+        _check_tiling(self.periods, option=option)
 
     # -- what kind of tariff this is, DERIVED --------------------------------
     @property
@@ -477,7 +505,7 @@ class StaticProfile:
             u += timedelta(hours=1)
         if not out:
             raise ProfileInvalid(
-                f"static_profile.series({since.isoformat()}, "
+                f"{self.option}.series({since.isoformat()}, "
                 f"{until.isoformat()}) spans no whole hour. An empty series is "
                 f"not constructible downstream on purpose (price.py trap 3).")
         return out
@@ -489,7 +517,7 @@ class StaticProfile:
         return f"{kind}: " + "; ".join(p.words for p in self.periods)
 
 
-def _check_tiling(periods) -> None:
+def _check_tiling(periods, *, option: str = "static_profile") -> None:
     """Every day type must be covered by EXACTLY ONE period, every minute.
 
     ⚠️ REFUSES BOTH DIRECTIONS. A gap means an hour with no price, and the only
@@ -506,42 +534,47 @@ def _check_tiling(periods) -> None:
             if n > 1 and over_from is None:
                 over_from = (minute, n)
             if n != 0 and gap_from is not None:
-                _raise_gap(weekday, gap_from, minute)
+                _raise_gap(weekday, gap_from, minute, option)
             if n <= 1 and over_from is not None:
-                _raise_overlap(weekday, over_from, minute, periods)
+                _raise_overlap(weekday, over_from, minute, periods, option)
         if gap_from is not None:
-            _raise_gap(weekday, gap_from, MINUTES_PER_DAY)
+            _raise_gap(weekday, gap_from, MINUTES_PER_DAY, option)
         if over_from is not None:
-            _raise_overlap(weekday, over_from, MINUTES_PER_DAY, periods)
+            _raise_overlap(weekday, over_from, MINUTES_PER_DAY, periods, option)
 
 
 def _hhmm(m):
     return f"{m // 60:02d}:{m % 60:02d}"
 
 
-def _raise_gap(weekday, start, end):
+def _raise_gap(weekday, start, end, option="static_profile"):
     raise ProfileInvalid(
-        f"static_profile leaves {DAY_NAMES[weekday]} "
+        f"{option} leaves {DAY_NAMES[weekday]} "
         f"{_hhmm(start)}-{_hhmm(end)} with no period, so those hours have no "
-        f"price. Refused rather than defaulted: an invented price is one an "
-        f"optimiser would trade on, and §11.4 already says what a missing price "
-        f"means. Add a period covering it - remember a window written "
-        f"\"22:00-07:00 mon-fri\" does NOT cover Saturday morning.")
+        f"price. Add a period that covers them.")
 
 
-def _raise_overlap(weekday, over, end, periods):
+def _raise_overlap(weekday, over, end, periods, option="static_profile"):
     start, n = over
     names = [p.name for p in periods if p.covers(weekday, start)]
     raise ProfileInvalid(
-        f"static_profile gives {DAY_NAMES[weekday]} {_hhmm(start)}-"
-        f"{_hhmm(end)} {n} prices at once ({', '.join(names)}). Two prices for "
-        f"one hour means one of them silently wins on list order. Narrow one of "
-        f"the windows or split the day selector.")
+        f"{option} gives {DAY_NAMES[weekday]} {_hhmm(start)}-"
+        f"{_hhmm(end)} {n} prices at once ({', '.join(names)}). Make the "
+        f"periods stop overlapping.")
 
 
-def parse_static_profile(value):
+def parse_static_profile(value, *, option: str = "static_profile",
+                         means: str = None):
     """`static_profile` -> a `StaticProfile`, or None when unset.
 
+    ⚠️ TARIFF-17 MADE `option`/`means` PARAMETERS RATHER THAN FORKING THIS
+    FUNCTION, and that is the whole of the reuse. A second period parser would
+    be a second tiling rule, a second day-type rule and a second set of DST
+    bugs, diverging first on the 23- and 25-hour days where nobody looks. The
+    two arguments move only the OPTION NAME and the "what this number is"
+    clause through the refusals; the grammar, the tiling check and the wrapping
+    rule are one implementation with one set of checks over it.
+
     Accepts what the option can actually arrive as:
       * `None` / `""` / `"null"`      - unset. §14 ships `static_profile: null`.
       * a JSON string                 - what config.yaml's flat `str?` option
@@ -555,6 +588,8 @@ def parse_static_profile(value):
     """
     if value is None:
         return None
+    if means is None:
+        means = _PERIOD_MEANS.get(option, _PERIOD_MEANS["static_profile"])
     if isinstance(value, str):
         text = value.strip()
         if not text or text.lower() in ("null", "none", "off"):
@@ -563,42 +598,35 @@ def parse_static_profile(value):
             value = json.loads(text)
         except ValueError as e:
             raise ProfileInvalid(
-                f"static_profile is not valid JSON ({e}). It is a JSON object "
-                f"with a \"periods\" list, on one line, e.g.\n"
-                f'  {{"periods": [{{"name":"day","from":"07:00","to":"22:00",'
-                f'"days":"mon-fri","eur_per_kwh":0.34}}, ...]}}\n'
-                f"Leave it empty for a dynamic-only or price-free site.")
+                f"{messages.not_valid(option, e)}. Copy the example from the "
+                f"documentation, or leave it empty if you have no fixed "
+                f"tariff.")
 
     if isinstance(value, dict):
         tz = str(value.get("timezone", "") or "").strip().lower()
         if tz not in SUPPORTED_TZ:
             raise ProfileInvalid(
-                f"static_profile.timezone is {value.get('timezone')!r}. Only "
-                f"Europe/Brussels is supported: the shipped image carries no tz "
-                f"database (see app/price.py), so any other zone could not be "
-                f"honoured and would be silently treated as Brussels - which is "
-                f"wrong by an hour for part of the year.")
+                f"{option}.timezone is {value.get('timezone')!r}. Only "
+                f"Europe/Brussels is supported.")
         rows = value.get("periods")
         if rows is None:
             raise ProfileInvalid(
-                "static_profile has no \"periods\" list. Even a fully-fixed "
-                "tariff is written as one period covering 00:00-24:00 all days "
-                "- one shape for both products, so nothing downstream branches "
-                "on which kind of site this is.")
+                f"{option} has no \"periods\" list. A fixed price is one "
+                f"period from 00:00 to 24:00 on all days.")
     else:
         rows = value
 
     if not isinstance(rows, (list, tuple)):
         raise ProfileInvalid(
-            f"static_profile.periods is {type(rows).__name__}, not a list")
+            f"{option}.periods is {type(rows).__name__}, not a list")
 
     periods = []
     for i, row in enumerate(rows, start=1):
         if not isinstance(row, dict):
             raise ProfileInvalid(
-                f"static_profile.periods[{i}] is {type(row).__name__}, not an "
+                f"{option}.periods[{i}] is {type(row).__name__}, not an "
                 f"object with from/to/days/eur_per_kwh")
-        where = f"static_profile.periods[{i}]"
+        where = f"{option}.periods[{i}]"
         name = str(row.get("name", "") or f"period{i}").strip() or f"period{i}"
         start = _minutes(row.get("from", row.get("start")), f"{where}.from")
         end = _minutes(row.get("to", row.get("end")), f"{where}.to")
@@ -617,8 +645,47 @@ def parse_static_profile(value):
                               end_min=end,
                               days=_days(row.get("days"), f"{where}.days"),
                               eur_per_kwh=_price(row.get("eur_per_kwh"),
-                                                 f"{where}.eur_per_kwh")))
-    return StaticProfile(periods)
+                                                 f"{where}.eur_per_kwh",
+                                                 means)))
+    return StaticProfile(periods, option=option)
+
+
+def parse_taxes_profile(value):
+    """`price_taxes_profile` -> a `StaticProfile` of TAX values, or None.
+
+    TARIFF-17. THE DEFECT THIS EXISTS TO CLOSE: `price.py` modelled the whole
+    non-energy part of a Belgian bill as ONE scalar. In Flanders that is
+    correct - Fluvius distribution is a single rate and its tariff card offers
+    only `Normaal | Uitsl. nacht`, where *exclusive night* is a separate
+    physical circuit rather than a night register. The Walloon and Brussels
+    DSOs are on the same card with four columns - `Enkelvoudig | Dag | Nacht |
+    Uitsl. nacht` - and the day/night gap is real money:
+
+        ORES          dag 13,27  nacht  7,39  ->  5,88 c EUR/kWh
+        AIESH         dag 15,17  nacht  8,21  ->  6,96
+        Tecteo RESA   dag 12,20  nacht  7,01  ->  5,19
+        Sibelga (BXL) dag  9,39  nacht  7,10  ->  2,29
+        ORES IMPACT   dag 16,578 nacht  5,090 -> 11,49   (2026)
+
+    ⚠️ AND THE BANDS ARE ANTI-CORRELATED WITH WHAT THE BATTERY WANTS TO DO.
+    The cheap network hours are the cheap spot hours, so flattening them does
+    not merely shift the curve - it SYSTEMATICALLY UNDERSTATES the true spread
+    and makes the add-on decline cycles that are genuinely profitable. See
+    DOCS.md "The three buckets" for why the flat scalar could never have done
+    this: an additive constant, identical every hour, cancels exactly in
+    `max - min` and cannot move `min(firm, key=...)` either.
+
+    ⚠️ THE VALUE IS THE TAXES COMPONENT, NOT AN ALL-IN PRICE. `static_profile`
+    uses the same grammar for an all-in figure; the two are one parser and two
+    meanings, and `_price()`'s refusal names which one it wanted.
+
+    ⚠️ NOT PARSED ON THE FETCH PATH. validate.py refuses a malformed table at
+    STARTUP, by the rule `price.py` trap 3 states for `static_profile`: a table
+    that cannot be parsed at 03:00 is a site that stops pricing at 03:00, and
+    §11.4 makes that quiet.
+    """
+    return parse_static_profile(value, option=TAXES_PROFILE_OPTION,
+                                means=_TAXES_MEANS)
 
 
 # --------------------------------------------------------------------------- #
@@ -1052,18 +1119,39 @@ class TariffPlan:
         for 76 % of a 40-hour soak and mixed 900/3600 s for 70 %, and no HTTP
         surface said either.
         """
+        # UX-08: plain words, every figure in its own slot as before.
         if not self.has_prices:
-            return f"no tariff - {self.read.reason}"
-        tag = {"provider": self.read.provider, "static": "static_profile",
-               "fallback": "static_profile (feed down)"}.get(self.origin,
-                                                             self.origin)
+            return f"no prices, {self.read.reason}"
+        tag = {"provider": "the price feed", "static": "your fixed tariff",
+               "fallback": "your fixed tariff, because the feed is down"}.get(
+                   self.origin, self.origin)
+        what = {PriceProduct.DAY_AHEAD: "day-ahead prices",
+                PriceProduct.REALTIME: "real-time prices",
+                PriceProduct.STATIC: "day/night prices",
+                PriceProduct.FIXED: "a fixed price"}.get(self.product,
+                                                         str(self.product))
+        # UX-10: the spacing in words, and no "not final yet": a plan is
+        # provisional exactly when it holds an estimated price, which the
+        # count already says.
         gaps = self.spacings_s
-        return (f"{self.product.value} from {tag}, "
-                f"{self.n_points} points over {self.hours} h, "
-                f"{self.n_firm} firm / {self.n_carried} carried"
-                + (f", {'+'.join(str(g) for g in gaps)} s spacing"
-                   if gaps else "")
-                + (", provisional" if self.provisional else ""))
+        return (f"{what} from {tag}, "
+                f"{self.n_points} prices over {self.hours} hours, "
+                f"{self.n_firm} published and {self.n_carried} estimated"
+                + (f", {spacing_words(gaps)}" if gaps else ""))
+
+
+def spacing_words(gaps) -> str:
+    """`(900, 3600)` -> `one every 15 minutes or every hour`."""
+    def one(s):
+        s = int(s)
+        if s == 3600:
+            return "every hour"
+        if s % 3600 == 0:
+            return f"every {s // 3600} hours"
+        if s % 60 == 0:
+            return f"every {s // 60} minutes"
+        return f"every {s} seconds"
+    return "one " + " or ".join(one(g) for g in gaps)
 
 
 def _whole_hours(points) -> int:
@@ -1133,9 +1221,9 @@ def static_plan(opts: dict, since: datetime, until: datetime, *,
     if profile is None:
         return TariffPlan(
             PriceRead.no_data(
-                "no static_profile configured; §11.4: plan provisional, no "
-                "arbitrage. Self-consumption, peak shaving and reserve "
-                "management are unaffected"),
+                "no fixed tariff is set, so the plan is estimated and there "
+                "is no trading. Self-consumption, peak limiting and the "
+                "reserve are not affected"),
             None, "none")
     points = profile.series(since, until, provisional=provisional)
     return TariffPlan(
@@ -1157,21 +1245,22 @@ def static_status(opts: dict, now: datetime):
         plan = static_plan(opts, now, now + timedelta(days=MEAN_WINDOW_DAYS),
                            now=now)
     except ProfileInvalid as e:
-        _LOG.warning("static_profile is unusable (%s); no cheap window. This "
-                     "should have been refused at startup - see validate.py", e)
-        return False, f"static_profile unusable: {e}"
+        _LOG.warning("static_profile cannot be used (%s), so there is no "
+                     "cheap window. The start-up check should have refused "
+                     "it.", e)
+        return False, f"Fixed tariff cannot be used: {e}"
     if not plan.has_prices:
-        return False, "no static profile"
+        return False, "No fixed tariff set"
     cheap = plan.cheap_now(now)
     window = plan.window_at(now)
     price = plan.price_at(now)
     when = plan.profile.next_change(now)
     until = "" if when is None else f" until {brussels(when):%H:%M}"
-    kind = ("fixed" if plan.product is PriceProduct.FIXED else "day/night")
-    return cheap, (f"{kind}: {window}{until} at {price:.4f} EUR/kWh, "
-                   f"mean {plan.mean_eur_kwh():.4f} over "
-                   f"{MEAN_WINDOW_DAYS} d - "
-                   f"{'CHEAP window' if cheap else 'not a cheap window'}")
+    kind = ("Fixed" if plan.product is PriceProduct.FIXED else "Day/night")
+    return cheap, (f"{kind} tariff, {window}{until}: {price:.4f} EUR/kWh, "
+                   f"{'cheap' if cheap else 'not cheap'} against the "
+                   f"{MEAN_WINDOW_DAYS}-day average of "
+                   f"{plan.mean_eur_kwh():.4f}")
 
 
 async def resolve_tariff(opts: dict, since: datetime, until: datetime,
@@ -1264,17 +1353,18 @@ def _degrade(opts, read, since, until, stamp) -> TariffPlan:
     try:
         profile = parse_static_profile(price_option(opts, "static_profile"))
     except ProfileInvalid as e:
-        _LOG.warning("the price feed is down AND static_profile is unusable "
-                     "(%s), so there is no tariff at all", e)
+        _LOG.warning("The price feed is down and the fixed tariff "
+                     "(static_profile) cannot be used either (%s), so there is "
+                     "no tariff at all.", e)
         profile = None
     if profile is None:
-        _LOG.warning("§11.4: %s, and no static_profile is configured to fall "
-                     "back to. The plan is provisional and arbitrage is off; "
-                     "self-consumption, peak shaving and reserve management "
-                     "continue (§6, §10.1).", read.reason)
+        _LOG.warning("The price feed failed and no fixed tariff is set, so "
+                     "trading is off, while peak limiting and home use go on. "
+                     "%s.", read.reason)
         return TariffPlan(read, None, "none")
-    _LOG.warning("§11.4: %s - falling back to the static profile, plan marked "
-                 "PROVISIONAL, arbitrage off.", read.reason)
+    _LOG.warning("The price feed failed, so the fixed tariff is used "
+                 "instead, marked as estimated, and trading is off. %s.",
+                 read.reason)
     points = profile.series(since, until, provisional=True)
     return TariffPlan(
         PriceRead.series(points, profile.product, "static_profile", stamp),

goodwe_controller/app/store.py

@@ -222,6 +222,8 @@ class MigrationReport:
         self.misdirected = []
         # Why nothing ran, when nothing ran. Empty means "already at schema".
         self.skipped = ""
+        # The inverter list the moves were graded against, for `explain()`.
+        self.roster = []
 
     @property
     def ok(self) -> bool:
@@ -237,19 +239,27 @@ class MigrationReport:
             # the flat keys ARE its namespace - and an operator reading the
             # startup log needs to be told which, because only one of them
             # changes when a second inverter is declared.
-            return self.skipped or (f"store already at schema "
-                                    f"{self.from_version}; no "
-                                    f"per-inverter migration needed")
-        out = (f"migrated {len(self.moved)} flat key(s) to inverter "
-               f"namespaces: " + ", ".join(sorted(self.moved)))
+            return self.skipped or (f"the saved state is already at version "
+                                    f"{self.from_version}, so nothing moves")
+        # UX-10: plain sentences (test_messages.py part 6). Each problem is
+        # named by its key and what went wrong, and `problems`, `lost` and
+        # `misdirected` keep their full notes for the checks that read them.
+        n = len(self.moved)
+        out = (f"moved {n} saved {'value' if n == 1 else 'values'} to one part "
+               f"per inverter: " + ", ".join(sorted(self.moved)) if n
+               else "moved nothing")
         if self.kept:
-            out += " (left alone, already namespaced: " + ", ".join(sorted(self.kept)) + ")"
-        if self.problems:
-            out += " - PROBLEMS: " + "; ".join(self.problems)
-        if self.lost:
-            out += " - STATE LOST: " + "; ".join(self.lost)
-        if self.misdirected:
-            out += " - WRONG NAMESPACE: " + "; ".join(self.misdirected)
+            out += ". Already in place: " + ", ".join(sorted(self.kept))
+        def keys(notes):
+            return ", ".join(note.split(" ", 1)[0] for note in notes)
+        other = [n for n in self.problems
+                 if n not in self.lost and n not in self.misdirected]
+        parts = ([f"lost {keys(self.lost)}"] if self.lost else []) + (
+            [f"moved under an inverter not in the list {self.roster!r}: "
+             f"{keys(self.misdirected)}"] if self.misdirected else []) + (
+            [f"read back differently {keys(other)}"] if other else [])
+        if parts:
+            out += ". Problems: " + ", and ".join(parts)
         return out
 
 
@@ -328,8 +338,8 @@ def migrate_unit_keys(store, unit: str, roster=None) -> MigrationReport:
         # ⚠️ NOT MARKED DONE. A migration that lost state must run again on the
         # next start rather than be recorded as finished - the one thing worse
         # than a failed migration is a failed migration a later version skips.
-        _LOG.error("per-inverter store migration LOST STATE and has not been "
-                   "marked done: %s", rep.explain())
+        _LOG.error("Moving the saved state to one part per inverter lost "
+                   "data, so it is not marked done: %s", rep.explain())
     return rep
 
 
@@ -436,6 +446,7 @@ def _verify_moves(store, rep: MigrationReport, roster=None) -> None:
     if roster is None:
         return
     names = [str(n) for n in roster]
+    rep.roster = names
     # `unit_key()` builds `unit/<unit>/<key>`, so the unit is field 1. Split
     # through the same spelling the writer used rather than re-deriving it.
     #
@@ -469,8 +480,8 @@ def _verify_moves(store, rep: MigrationReport, roster=None) -> None:
         if unit in names:
             continue
         rep.verified = False
-        note = (f"{target} was migrated into namespace {unit!r}, which is NOT "
-                f"on the roster {names!r} - nothing reads that key")
+        note = (f"{target} was moved under {unit!r}, which is not in the "
+                f"inverter list {names!r}, so nothing reads it")
         rep.problems.append(note)
         rep.misdirected.append(note)
 
@@ -536,14 +547,12 @@ def migrate_maint_keys(store, unit: str, roster) -> MigrationReport:
     names = [str(n) for n in roster]
     rep.from_version = int(data.get(MAINT_SCHEMA_KEY, 0) or 0)
     if len(names) <= 1:
-        rep.skipped = ("one inverter: the flat maintenance keys ARE that pack's "
-                       "history and are read in place, so there is nothing to "
-                       "move and the store layout does not change")
+        rep.skipped = ("one inverter, so it is read where it is and nothing "
+                       "moves")
         return rep
     if rep.from_version >= MAINT_SCHEMA_VERSION:
-        rep.skipped = (f"maintenance history already at schema "
-                       f"{rep.from_version}; written by a multi-inverter "
-                       f"version and not touched")
+        rep.skipped = (f"already at version {rep.from_version}, written for "
+                       f"several inverters, so it is left as it is")
         return rep
 
     rep.ran = True
@@ -567,8 +576,8 @@ def migrate_maint_keys(store, unit: str, roster) -> MigrationReport:
         # the re-run a no-op where the keys did land, so refusing the marker
         # costs one repeated pass and buys the difference between a migration
         # that can still be fixed and one the store says already happened.
-        _LOG.error("per-pack maintenance-history migration did NOT land and "
-                   "has not been marked done: %s", rep.explain())
+        _LOG.error("Moving the maintenance history to one part per inverter "
+                   "did not work, so it is not marked done: %s", rep.explain())
     return rep
 
 
@@ -576,6 +585,9 @@ class Store:
     def __init__(self, path: str = "/data/state.json"):
         self.path = path
         self.data = dict(DEFAULTS)
+        # UX-13 P4: True when this boot found no state file, i.e. a new /data.
+        # Only the setup wizard's first-run rule reads it (uipage.setup_needed).
+        self.fresh = False
         self.load()
 
     def load(self) -> None:
@@ -589,6 +601,7 @@ class Store:
                           self.data.get("phase"), self.data.get("last_completed"),
                           self.data.get("sign_tripped"))
         except FileNotFoundError:
+            self.fresh = True
             _LOG.info("no saved state, starting fresh")
         except (json.JSONDecodeError, OSError) as err:
             # A corrupt state file must not stop the controller: losing the

goodwe_controller/app/tariff.py

@@ -114,6 +114,8 @@ import sqlite3
 from dataclasses import dataclass
 from datetime import datetime, timedelta, timezone, tzinfo
 
+from . import messages
+
 _LOG = logging.getLogger("goodwe.tariff")
 
 QUARTER_S = 900
@@ -339,8 +341,8 @@ class PeakStore:
             # INFO, not ERROR: on a dev host or in a test container there is no
             # /data and nothing is wrong. A store that OPENED and then broke is
             # the error case, and it is logged as one below.
-            _LOG.info("no peak store: %s - the monthly peak will read "
-                      "NOT_OBSERVED", self.last_error)
+            _LOG.info("No peak store (%s), so the month peak cannot be read "
+                      "and only the peak limit is used.", self.last_error)
             return
         try:
             self._db = sqlite3.connect(self.path, timeout=5.0,
@@ -360,8 +362,9 @@ class PeakStore:
             # fault must not stop a controller that is regulating a battery. The
             # cost of continuing is a peak that reads NOT_OBSERVED, and every
             # reader is built to treat that as "do not use me", not as 0 W.
-            _LOG.error("peak store unusable at %s (%s) - the monthly peak will "
-                       "read NOT_OBSERVED, which is not a zero peak", self.path, err)
+            _LOG.error("The peak store at %s cannot be used (%s), so only the "
+                       "peak limit is used. The month peak is unknown, not "
+                       "zero.", self.path, err)
 
     def close(self) -> None:
         if self._db is not None:
@@ -672,12 +675,12 @@ class PeakTracker:
         now = now or datetime.now(timezone.utc)
         snap = self.store.load_partial()
         if not snap:
-            self.restore_state = ("fresh: no checkpoint" if self.store.ok
-                                  else "fresh: store unreadable")
+            self.restore_state = ("fresh start, nothing saved" if self.store.ok
+                                  else "fresh start, the store cannot be read")
             return self.restore_state
         block = snap.get("block")
         if block is None:
-            self.restore_state = "fresh: checkpoint had no open block"
+            self.restore_state = "fresh start, no open 15-minute period saved"
             return self.restore_state
 
         current = int(now.timestamp() // QUARTER_S) * QUARTER_S
@@ -686,11 +689,13 @@ class PeakTracker:
                 # A reshaped accumulator (meter_phases changed) is a different
                 # measurement, not a resumable one. Say so; do not half-resume.
                 self.store.clear_partial()
-                self.restore_state = "fresh: checkpoint does not fit this averager"
+                self.restore_state = ("fresh start, the saved period does not "
+                                      "fit the number of phases")
                 return self.restore_state
             self.restore_state = (
-                f"resumed the open block at {snap.get('elapsed', 0.0):.0f} s "
-                f"of {QUARTER_S} s ({snap.get('acc', 0.0) / QUARTER_S:.0f} W banked)")
+                f"resumed the open 15-minute period at "
+                f"{snap.get('elapsed', 0.0):.0f} s of {QUARTER_S} s, with "
+                f"{snap.get('acc', 0.0) / QUARTER_S:.0f} W counted so far")
             return self.restore_state
 
         # The block ended while the add-on was down. Its measured part really
@@ -704,10 +709,14 @@ class PeakTracker:
                                      if snap.get("pp_acc") and snap.get("last_pp") else None))
         banked = self.store.record_block(closed, self.policy)
         self.store.clear_partial()
+        # UX-10: plain words and the local time, not ISO and "banked".
         self.restore_state = (
-            f"closed a stale block from {closed.start.isoformat()} at "
-            f"{closed.offtake_avg_w:.0f} W (partial coverage), "
-            + ("banked" if banked else "NOT banked - store unwritable"))
+            f"closed the 15-minute period from "
+            f"{messages.when(closed.start.astimezone(BILLING_TZ))} at "
+            f"{closed.offtake_avg_w:.0f} W, partly measured, "
+            + ("and saved it" if banked
+               else "but could not save it, because the store cannot be "
+                    "written"))
         return self.restore_state
 
     # -- steady state -------------------------------------------------------

goodwe_controller/app/ui_text/en.json

@@ -0,0 +1,215 @@
+{
+  "groups": {
+    "meter": {"name": "Meter", "description": "Where the grid reading comes from."},
+    "inverters": {"name": "Inverters and batteries", "description": "The inverters the add-on controls, and your solar."},
+    "tariff": {"name": "Tariff and prices", "description": "What you pay and are paid per kWh."},
+    "safety": {"name": "Safety limits", "description": "The peak limit, starting and stopping, and the safety stops."},
+    "maintenance": {"name": "Maintenance", "description": "The monthly battery cycle and the log."},
+    "tuning": {"name": "Control tuning", "description": "For support only, because these were measured on real hardware."}
+  },
+  "parts": {
+    "meter.timing": {"name": "Timing"},
+    "inverters.solar": {"name": "Solar"},
+    "tariff.selling": {"name": "Charging and selling on price"},
+    "tariff.feed": {"name": "Price feed details"},
+    "safety.peak": {"name": "Peak limit"},
+    "safety.start": {"name": "Starting and stopping"},
+    "safety.stops": {"name": "Safety stops", "description": "Measured on real hardware, so leave them unchanged."},
+    "maintenance.support": {"name": "Support"}
+  },
+  "fields": {
+    "solar": {"name": "Solar inverters", "description": "Each solar inverter's power sensor, which the add-on records but does not use for control."},
+    "contract": {"name": "Your contract", "description": "How your supplier prices each kWh you take from the grid."},
+    "region": {"name": "Region", "description": "Fills in grid costs, levies and VAT for the year shown, but not yet for Wallonia or Brussels, so check your bill."},
+    "fallback": {"name": "Price when the feed is down", "description": "Used when the price source does not answer."},
+    "fixed_price": {"name": "Price per kWh, all in", "description": "Energy, supplier costs, grid costs, levies and VAT together."},
+    "day_price": {"name": "Day price, weekdays 07:00 to 22:00", "description": "All in, as on your bill."},
+    "night_price": {"name": "Night and weekend price", "description": "All in, as on your bill."}
+  },
+  "choices": {
+    "contract": {"none": "No prices", "fixed": "Fixed price", "daynight": "Day and night", "dynamic": "Dynamic, hourly", "custom": "Other time windows"},
+    "fallback": {"none": "None", "fixed": "One price", "daynight": "Day and night", "custom": "Other time windows"},
+    "region": {"flanders": "Flanders, Fluvius Antwerpen", "own": "I enter my own figure"},
+    "meter_source": {"off": "One grid power entity", "ha_dsmr": "Import and export entities", "mqtt_p1": "Meter over MQTT", "ha_signed": "One net power entity", "homewizard_local": "HomeWizard meter on the network"},
+    "meter_phases": {"1": "1 phase", "3": "3 phases"},
+    "shadow_mode": {"auto": "Automatic", "on": "Always on", "off": "Off"},
+    "price_provider": {"generic_dayahead": "Day-ahead market price", "custom_formula": "Your own price formula", "manual_csv": "A price file"},
+    "log_level": {"trace": "Everything, for support", "debug": "Detailed, to find a problem", "info": "Normal", "warning": "Warnings and errors", "error": "Errors only"}
+  },
+  "applies": {
+    "restart": {"name": "Applies after a restart"},
+    "now": {"name": "Applies right away"}
+  },
+  "home": {
+    "app": {"name": "Battery add-on"},
+    "tabs": {"home": "Home", "batteries": "Batteries", "settings": "Settings", "setup": "Setup", "label": "Screens"},
+    "now": {"name": "Now", "description": "Updated every 3 seconds.", "solar": "Solar", "house": "House", "grid": "Grid", "batteries": "Batteries"},
+    "plan": {
+      "name": "Today's plan",
+      "description": "Point at a bar or a block for details, or tap it on a phone.",
+      "cheap": "Low price",
+      "dear": "High price",
+      "estimate": "Estimate",
+      "grid": "Charges from the grid",
+      "give": "Gives power",
+      "cycle": "Monthly battery cycle",
+      "peak": "Peak limit",
+      "house": "Follows the house",
+      "now": "now",
+      "time_to": "to",
+      "per_kwh": "per kWh",
+      "cheap_tip": "low for today",
+      "dear_tip": "high for today",
+      "estimate_tip": "estimate from yesterday",
+      "none_tip": "No price known",
+      "no_prices": {"description": "No prices for today, so the chart shows only the plan."},
+      "list": "The plan in words",
+      "average_tip": "hour average"
+    },
+    "peak": {"name": "Peak limit", "this_month": "This month's peak", "limit": "Limit", "none": "None recorded yet", "unreadable": "Cannot be read now"},
+    "attention": {"name": "Needs attention", "nothing": "Nothing to look at", "to_look": "to look at", "details": "Details", "alarm": "Alarm", "warning": "Warning", "info": "Info"},
+    "control": {"name": "Control", "stop": "Stop control", "start": "Start control", "maint_start": "Start a battery cycle now", "maint_abort": "Stop the battery cycle", "docs": "Add-on documentation", "more": "More actions"},
+    "details": {"name": "Details for installers", "rows": "Status rows", "checks": "Checks", "event": "Last event"},
+    "dialog": {
+      "cancel": "Cancel",
+      "stop": {"name": "Stop control?", "description": "Every inverter is set to 0 W until you start control again.", "yes": "Stop control"},
+      "start": {"name": "Start control?", "description": "The add-on controls the batteries again and clears any safety stop.", "yes": "Start control"},
+      "maint_start": {"name": "Start a battery cycle?", "description": "The battery empties, refills and holds full, which takes a few hours.", "yes": "Start the cycle"},
+      "maint_abort": {"name": "Stop the battery cycle?", "description": "Every inverter is set to 0 W for a moment, then control carries on.", "yes": "Stop the cycle"}
+    },
+    "toast": {"started": "Control started.", "stopped": "Control stopped.", "done": "Done.", "failed": "That did not work. Try again."},
+    "offline": {"name": "Cannot reach the add-on", "description": "The page tries again every 3 seconds."},
+    "batteries": {"name": "Batteries", "description": "Battery modes and on and off switches arrive in a later update.", "level": "Level", "now": "Now", "stored": "Stored", "mode": "Mode", "settings": "Change inverter settings"},
+    "settings": {"name": "Settings", "description": "The settings are grouped by task below.", "open": "Open the settings page"}
+  },
+  "choices_later": {
+    "region": {"wallonia": "Wallonia, no preset yet", "brussels": "Brussels, no preset yet"}
+  },
+  "choice_help": {
+    "meter_source": {
+      "off": {"description": "A Home Assistant entity that reads grid power in W, positive when you take from the grid."},
+      "ha_dsmr": {"description": "Two Home Assistant entities from the DSMR integration, one for import and one for export."},
+      "mqtt_p1": {"description": "The meter's readings arrive over MQTT on a topic you name."},
+      "ha_signed": {"description": "One Home Assistant entity that reads net grid power, positive for import."},
+      "homewizard_local": {"description": "The add-on reads a HomeWizard meter on your network, and can spot a stuck meter."}
+    }
+  },
+  "settings": {
+    "name": "Settings",
+    "description": "Every setting, grouped by task, and the simple view follows in a later update.",
+    "classic": "Classic settings",
+    "search": {"name": "Find a setting", "description": "Find a setting, for example peak or meter."},
+    "no_match": {"description": "No setting matches your search."},
+    "loading": "Loading the settings",
+    "load_failed": {"name": "Cannot read the settings", "description": "The add-on could not read its stored settings, so use Classic settings or the Configuration tab."},
+    "footer": {"description": "Every change is checked by the add-on's own start checks before it is saved."},
+    "to_fix": "to fix",
+    "to_check": "to check",
+    "changed": "changed",
+    "on": "On",
+    "off": "Off",
+    "not_set": "Not set",
+    "locked": "Locked",
+    "change": "Change",
+    "support": {"description": "These were measured on real hardware, so change them only when support asks."},
+    "picker": {
+      "choose": "Choose an entity",
+      "search": {"description": "Search by name or entity id."},
+      "all": "Show every entity",
+      "use": "Use this entity id",
+      "clear": "Clear",
+      "missing": "Not in Home Assistant",
+      "none": {"description": "Nothing matches, so check the entity in Developer Tools."}
+    },
+    "add_inverter": "Add an inverter",
+    "inverter": "Inverter",
+    "remove": "Remove",
+    "add_row": "Add a row",
+    "add_solar": "Add a solar inverter",
+    "reversed": "Reads negative",
+    "phase": "Phase",
+    "raw_roster": {"description": "This inverter list can only be changed in the Configuration tab."},
+    "region_year": "{year} figures",
+    "hour": "{hour}:00 UTC",
+    "preset": {"description": "Filled in by the region above, so choose your own figure to change it."},
+    "cycle": {"name": "Run a cycle by hand", "description": "The same actions as on Home, each asking first."},
+    "savebar": {"label": "Unsaved changes", "one": "change not saved", "many": "changes not saved", "discard": "Discard", "save": "Save", "saving": "Saving"},
+    "saved": {"name": "Saved, not running yet", "description": "The add-on runs the settings it started with until you restart it."},
+    "differs": {"name": "Stored settings are not running", "description": "Some stored settings differ from what runs now, so restart the add-on to apply them."},
+    "stale": {"name": "Changed somewhere else", "description": "These settings changed elsewhere while you edited, so save again to keep yours or discard to load theirs."},
+    "other": "Other messages",
+    "restart": "Restart now",
+    "dialog": {"name": "Restart the add-on?", "description": "Every inverter is set to 0 W while the add-on restarts, and then the new settings apply.", "yes": "Restart now"},
+    "toast": {
+      "saved": "Saved. Restart to apply.",
+      "discarded": "Changes discarded.",
+      "failed": "That did not work. Try again.",
+      "blocked": {"description": "Fix the settings marked in red, then save again."},
+      "restarting": {"description": "Restart requested, so this page stops answering for a moment."}
+    },
+    "tier": {"bad": "Must fix", "warn": "Check this", "info": "Note", "ok": "Passed"},
+    "derive": {
+      "raw_roster": {"description": "This inverter list can only be changed in the Configuration tab."},
+      "no_inverter": {"description": "Add at least one inverter."},
+      "flat_named": {"description": "Add a second inverter before naming this one."},
+      "no_source": {"description": "Choose where the dynamic prices come from."},
+      "custom_profile": {"description": "Other time windows can only be changed in the Configuration tab."},
+      "no_price": {"description": "Enter a price per kWh."},
+      "unknown": {"description": "The page cannot store this choice, so reload the page."}
+    },
+    "setup": {
+      "name": "Setup",
+      "description": "For installers: six steps to a working site, and each can be changed later under Settings.",
+      "done_before": {"description": "This site is set up already, so a change here replaces its stored settings."},
+      "step": "Step {n} of {total}",
+      "back": "Back",
+      "next": "Next",
+      "skip": "Next, or skip",
+      "finish": "Save and restart",
+      "not_now": "Not now",
+      "steps": {
+        "1": {"name": "Your meter", "description": "The add-on steers the grid reading to zero, so it needs your meter first."},
+        "2": {"name": "Inverters and batteries", "description": "One card for each inverter with a battery, with its entities in Home Assistant."},
+        "3": {"name": "Solar", "description": "Optional, so skip this step if the add-on should not record solar production."},
+        "4": {"name": "Prices", "description": "What you pay per kWh, so the batteries can charge when power is cheap."},
+        "5": {"name": "Peak limit", "description": "The grid stays under this limit, averaged over each 15-minute period."},
+        "6": {"name": "Check and start", "description": "The add-on checks everything with its own start checks, then restarts."}
+      },
+      "modes_later": {"description": "Choosing a mode for each battery comes in a later update."},
+      "kettle": {
+        "name": "Check the direction",
+        "description": "Read the meter, switch on a kettle, then read the meter again.",
+        "read": "Read the meter",
+        "again": "Read again",
+        "skip": "Skip this test",
+        "before": {"description": "The meter reads {w} now, so switch on a kettle and press Read again."},
+        "unread": {"description": "The meter cannot be read now, so check the entity and try again."},
+        "none": {"description": "The reading moved only {d}, so switch the kettle on and read again."},
+        "ok": {"description": "Good, the reading went up by {d} when the kettle came on."},
+        "flip": {"description": "The reading went down by {d}, so the add-on flips its sign for you."},
+        "wrong_signed": {"description": "The reading went down by {d}, so choose “One grid power entity” above, which can flip it."},
+        "wrong_dsmr": {"description": "The reading went down by {d}, so check that import and export are not swapped."},
+        "self": {"description": "The add-on reads this meter itself, so Home shows its direction after the restart."},
+        "skipped": {"description": "The meter direction is not tested, so check it on Home after the restart."},
+        "skipped_wrong": {"description": "The kettle test saw the meter reading go down, so check its direction in step 1 before you start control."},
+        "tested": {"description": "The meter direction was tested with a kettle."},
+        "needed": {"description": "Do the kettle test first, or skip it."}
+      },
+      "check": {
+        "name": "What the add-on checked",
+        "running": {"description": "Checking with the add-on's own start checks."},
+        "pass": {"description": "The add-on's start checks pass."},
+        "failed": {"description": "The check did not run, so try again."},
+        "again": "Check again",
+        "blocked": {"description": "Fix the items marked in red, then check again."}
+      },
+      "shadow": {"name": "Start in shadow mode", "description": "Recommended, because every inverter then stays at 0 W until you turn shadow mode off under Settings."},
+      "dialog": {"name": "Save and restart?", "description": "Every inverter is set to 0 W while the add-on restarts, and shadow mode keeps them at 0 W after that.", "yes": "Save and restart"},
+      "dialog_live": {"name": "Save and restart?", "description": "Every inverter is set to 0 W while the add-on restarts, and then the new settings apply.", "yes": "Save and restart"},
+      "done": {"name": "Setup is done", "description": "The add-on restarts in shadow mode now, so open Home in a minute to see what it would do."},
+      "done_live": {"name": "Setup is done", "description": "The add-on restarts now, so open Home in a minute to start control."},
+      "restart_failed": {"name": "Saved, not running yet", "description": "The restart did not go through, so press Restart now to apply the settings."},
+      "home": "Open Home"
+    }
+  }
+}

goodwe_controller/app/uilayout.py

@@ -0,0 +1,331 @@
+"""UX-13: the new page's layout, written once - screen, group, field.
+
+UI code names option keys only here and in uimodel.py, which holds the
+derivations this table lists (DECISIONS/UX-13-one-layout-table.md, amending
+UX-02 §3). Everything else stays where UX-02 put it: ranges in config.yaml's
+schema, rules in validate.py. test_uilayout.py fails CI when an option in
+config.yaml has no place here.
+
+A field's `key` is an option key, `inverters.<field>` for one inverter in the
+list, or `ui.<name>` for a page-only control that uimodel.py turns into options.
+The key is also its text key: label and help are translations/*.yaml's entry
+for an option, and app/ui_text's `fields.<name>` for a `ui.` field.
+"""
+
+from dataclasses import dataclass
+
+RESTART = "restart"         # stored options apply after a restart (UX-02 §5)
+NOW = "now"                 # runtime state (OPT-11's battery switches), none yet
+
+# Controls are names, not string literals, so a key is never followed by a
+# constant (test_defaults_pin.py reads `f("key", <constant>)` as a fallback).
+CHOICE, ENTITY, ENTITY_LIST, TOGGLE, SEGMENTED, SLIDER = (
+    "choice", "entity", "entity_list", "toggle", "segmented", "slider")
+NUMBER, TEXT, SELECT, LOCKED, INVERTER_LIST, SOLAR_LIST = (
+    "number", "text", "select", "locked", "inverter_list", "solar_list")
+CONTROLS = (CHOICE, ENTITY, ENTITY_LIST, TOGGLE, SEGMENTED, SLIDER, NUMBER,
+            TEXT, SELECT, LOCKED, INVERTER_LIST, SOLAR_LIST)
+# What an entity picker offers first. `power_w` is a power sensor the add-on
+# reads as watts with no unit conversion, so validate.py warns on a kW sensor.
+ENTITY_KINDS = ("power_w", "power", "energy", "pct", "number", "any")
+SHOW_OPS = ("==", "!=", "in", ">", "<")
+
+
+@dataclass(frozen=True)
+class Field:
+    key: str
+    control: str
+    unit: str = ""
+    scale: int = 1              # shown = stored / scale (the peak limit in kW)
+    step: float = 0             # slider or number step, stored units; 0 = 1
+    kind: str = ""              # entity picker filter, one of ENTITY_KINDS
+    show: tuple = ()            # ((name, op, value), ...), all must hold
+    applies: str = RESTART
+    simple: bool = False        # also on Settings, Simple
+    wizard: int = 0             # setup wizard step 1-6, 0 = not in the wizard
+    mirror: str = ""            # a choice also copied to this field, if offered
+    fills: str = ""             # a preset choice fills this field (uimodel)
+
+    @property
+    def text(self) -> str:
+        """Where the label and help live: `translations` or `ui_text`."""
+        return "ui_text" if self.key.startswith("ui.") else "translations"
+
+
+@dataclass(frozen=True)
+class Part:
+    id: str                     # "" is the group's main part
+    fields: tuple
+    collapsed: bool = False
+
+
+@dataclass(frozen=True)
+class Group:
+    id: str
+    parts: tuple
+    support_only: bool = False  # collapsed, with a "for support" warning
+
+
+def _src(*values):
+    return (("meter_source", "in", values),)
+
+
+_DYNAMIC = (("ui.contract", "==", "dynamic"),)
+_MAINT = (("maintenance_enabled", "==", True),)
+_ONE = (("inverter_count", "==", 1),)
+_SEVERAL = (("inverter_count", ">", 1),)
+_PHASES = (("meter_phases", ">", 1),)
+# One inverter stored flat has no name or capacity (uimodel._roster_encode).
+_LISTED = (("inverter_shape", "!=", "flat"),)
+
+# The per-inverter card. Its keys are `inverters.<field>` in config.yaml.
+ROSTER_FIELDS = (
+    Field("inverters.name", TEXT, show=_LISTED, wizard=2),
+    Field("inverters.setpoint_entity", ENTITY, kind="number", wizard=2),
+    Field("inverters.max_w", SLIDER, "W", step=100, wizard=2),
+    Field("inverters.bms_soc_floor", SLIDER, "%", wizard=2),
+    Field("inverters.soc_entity", ENTITY, kind="pct", wizard=2),
+    Field("inverters.batt_entity", ENTITY, kind="power_w", wizard=2),
+    Field("inverters.batt_invert", TOGGLE, wizard=2),
+    Field("inverters.capacity_kwh", NUMBER, "kWh", step=0.1, show=_LISTED,
+          wizard=2),
+)
+
+GROUPS = (
+    Group("meter", (
+        Part("", (
+            Field("meter_source", CHOICE, wizard=1),
+            Field("meter_entity", ENTITY, kind="power_w", show=_src("off"),
+                  wizard=1),
+            Field("meter_invert", TOGGLE, show=_src("off"), wizard=1),
+            Field("p1_net_entity", ENTITY, kind="power_w",
+                  show=_src("ha_signed"), wizard=1),
+            Field("p1_import_entity", ENTITY, kind="power_w",
+                  show=_src("ha_dsmr"), wizard=1),
+            Field("p1_export_entity", ENTITY, kind="power_w",
+                  show=_src("ha_dsmr"), wizard=1),
+            Field("p1_host", TEXT, show=_src("homewizard_local"), wizard=1),
+            Field("meter_mqtt_topic", TEXT, show=_src("mqtt_p1"), wizard=1),
+            Field("meter_phases", SEGMENTED, wizard=1),
+            Field("p1_phase_net_entities", ENTITY_LIST, kind="power_w",
+                  show=_src("ha_signed") + _PHASES, wizard=1),
+            Field("p1_phase_import_entities", ENTITY_LIST, kind="power_w",
+                  show=_src("ha_dsmr") + _PHASES, wizard=1),
+            Field("p1_phase_export_entities", ENTITY_LIST, kind="power_w",
+                  show=_src("ha_dsmr") + _PHASES, wizard=1),
+        )),
+        Part("timing", (
+            Field("meter_max_age_s", SLIDER, "s", step=5),
+            Field("meter_poll_s", SLIDER, "s",
+                  show=_src("homewizard_local")),
+        ), collapsed=True),
+    )),
+    Group("inverters", (
+        Part("", (Field("inverters", INVERTER_LIST, wizard=2),)),
+        # pv.py reads each entity's own unit, so a kW sensor is fine here.
+        Part("solar", (Field("ui.solar", SOLAR_LIST, kind="power",
+                             wizard=3),)),
+    )),
+    Group("tariff", (
+        Part("", (
+            # A contract without a feed is also the price used when a feed
+            # is down, so the fallback follows it (uimodel._tariff_encode).
+            Field("ui.contract", SEGMENTED, wizard=4, mirror="ui.fallback"),
+            Field("price_provider", SELECT, show=_DYNAMIC, wizard=4),
+            Field("price_formula", TEXT,
+                  show=_DYNAMIC + (("price_provider", "==", "custom_formula"),),
+                  wizard=4),
+            Field("price_csv_path", TEXT,
+                  show=_DYNAMIC + (("price_provider", "==", "manual_csv"),),
+                  wizard=4),
+            Field("ui.region", SELECT, wizard=4,
+                  fills="price_taxes_eur_kwh"),
+            Field("price_taxes_eur_kwh", NUMBER, "€/kWh", step=0.00001,
+                  wizard=4),
+            Field("price_markup_eur_kwh", NUMBER, "€/kWh", step=0.001,
+                  show=_DYNAMIC, wizard=4),
+            Field("export_price_eur_kwh", NUMBER, "€/kWh", step=0.001,
+                  wizard=4),
+            Field("price_export_formula", TEXT),
+            Field("ui.fallback", SEGMENTED, show=_DYNAMIC, wizard=4),
+            Field("ui.fixed_price", NUMBER, "€/kWh", step=0.01,
+                  show=(("ui.fallback", "==", "fixed"),), wizard=4),
+            Field("ui.day_price", NUMBER, "€/kWh", step=0.01,
+                  show=(("ui.fallback", "==", "daynight"),), wizard=4),
+            Field("ui.night_price", NUMBER, "€/kWh", step=0.01,
+                  show=(("ui.fallback", "==", "daynight"),), wizard=4),
+        )),
+        Part("selling", (
+            # OPT-11: derived from the batteries' selling switches once battery
+            # modes exist (uimodel.arbitrage_from_batteries). A toggle until then.
+            Field("arbitrage_enabled", TOGGLE),
+            Field("cycle_cost_threshold_eur", NUMBER, "€/kWh", step=0.01),
+            Field("arbitrage_soc_floor", SLIDER, "%"),
+            Field("arbitrage_soc_ceiling", SLIDER, "%"),
+        )),
+        Part("feed", (
+            Field("price_feed_url", TEXT, show=_DYNAMIC),
+            Field("price_horizon_h", SLIDER, "h", show=_DYNAMIC),
+            Field("price_timeout_s", SLIDER, "s", show=_DYNAMIC),
+            Field("price_now_entity", ENTITY, kind="any"),
+            Field("price_avg_entity", ENTITY, kind="any"),
+        ), collapsed=True),
+    )),
+    Group("safety", (
+        Part("peak", (
+            Field("peak_cap_w", SLIDER, "kW", scale=1000, step=100,
+                  simple=True, wizard=5),
+            Field("peak_forecast_entity", ENTITY, kind="power_w", wizard=5),
+            Field("peak_soc_floor", LOCKED, "%"),
+        )),
+        Part("start", (
+            Field("shadow_mode", SEGMENTED, simple=True, wizard=6),
+            Field("auto_start", TOGGLE),
+            Field("estop_fitted", TOGGLE),
+            Field("stale_input_s", SLIDER, "s"),
+            Field("meter_freeze_s", SLIDER, "s", step=30,
+                  show=_src("homewizard_local")),
+        )),
+        Part("stops", (
+            Field("sign_disagree_w", LOCKED, "W", step=10, show=_ONE),
+            Field("sign_disagree_s", LOCKED, "s", step=5, show=_ONE),
+            Field("unit_sign_disagree_w", LOCKED, "W", step=10,
+                  show=_SEVERAL),
+            Field("unit_sign_disagree_s", LOCKED, "s", step=5,
+                  show=_SEVERAL),
+            Field("site_sign_disagree_w", LOCKED, "W", step=10,
+                  show=_SEVERAL),
+            Field("site_sign_disagree_s", LOCKED, "s", step=5,
+                  show=_SEVERAL),
+            Field("circulation_w", LOCKED, "W", step=10, show=_SEVERAL),
+            Field("circulation_hold_s", LOCKED, "s", step=5, show=_SEVERAL),
+            Field("delivery_hold_s", LOCKED, "s", step=5, show=_SEVERAL),
+        ), collapsed=True),
+    )),
+    Group("maintenance", (
+        Part("", (
+            Field("maintenance_enabled", TOGGLE),
+            Field("maintenance_interval_days", SLIDER, "days", show=_MAINT),
+            Field("maintenance_start_hour", SELECT, show=_MAINT),
+            Field("maintenance_discharge_w", SLIDER, "W", step=100,
+                  show=_MAINT),
+            Field("maintenance_charge_w", SLIDER, "W", step=100,
+                  show=_MAINT),
+            Field("maintenance_soc_floor", SLIDER, "%", show=_MAINT),
+            Field("maintenance_soc_target", SLIDER, "%", show=_MAINT),
+            Field("maintenance_hold_min", SLIDER, "min", step=5,
+                  show=_MAINT),
+        )),
+        Part("support", (Field("log_level", SELECT),)),
+    )),
+    Group("tuning", (
+        Part("", (
+            Field("gain", LOCKED, step=0.05),
+            Field("slew_w", LOCKED, "W", step=50),
+            Field("deadband_w", LOCKED, "W"),
+            Field("target_grid_w", LOCKED, "W"),
+            Field("step_w", LOCKED, "W"),
+            Field("saturation_w", LOCKED, "W", step=10),
+            Field("saturation_cycles", LOCKED),
+            Field("integrator_max_w", LOCKED, "W", step=100),
+            Field("heartbeat_s", LOCKED, "s"),
+            Field("cycle_floor_s", LOCKED, "s"),
+        )),
+    ), support_only=True),
+)
+
+# --------------------------------------------------------------------------- #
+# UX-13 P4: the setup wizard. Its fields are the ones with `wizard=` above; this
+# is what the table cannot say per field (DECISIONS/UX-13-setup-wizard.md).
+# --------------------------------------------------------------------------- #
+WIZARD_STEPS = 6
+FINAL_STEP = WIZARD_STEPS       # a refusal on no wizard field is shown here
+OPTIONAL_STEPS = (3,)           # solar: "Next, or skip"
+
+# Step 1's kettle test. Per meter source Home Assistant reads: the page fields
+# read before and after a kettle is switched on, each with the sign it adds to
+# the grid reading, and what each direction means as (outcome, fields it
+# sets). Sets None: the options cannot fix it, so the step is not passed. A
+# source not listed is read by the add-on itself, so the page cannot test it.
+KETTLE_SOURCE = "meter_source"
+KETTLE_MIN_W = 500.0            # a kettle is 2 000 W, a house wobbles less
+KETTLE = {
+    "off": ((("meter_entity", 1),),
+            {"up": ("ok", {"meter_invert": False}),
+             "down": ("flip", {"meter_invert": True})}),
+    "ha_signed": ((("p1_net_entity", 1),),
+                  {"up": ("ok", {}), "down": ("wrong_signed", None)}),
+    "ha_dsmr": ((("p1_import_entity", 1), ("p1_export_entity", -1)),
+                {"up": ("ok", {}), "down": ("wrong_dsmr", None)}),
+}
+# Step 6 starts the site in shadow mode unless the installer switches it off:
+# (field, value when on, value when off).
+SHADOW = ("shadow_mode", "on", "auto")
+
+# Option keys the page never shows. uimodel.py writes each from page fields.
+DERIVED = {
+    "setpoint_entity": "inverters",       # one inverter, stored flat
+    "soc_entity": "inverters",
+    "batt_entity": "inverters",
+    "batt_invert": "inverters",
+    "max_w": "inverters",
+    "bms_soc_floor": "inverters",
+    "pv_entity": "ui.solar",              # one solar row, stored flat
+    "pv_entities": "ui.solar",
+    "pv_invert_entities": "ui.solar",     # the rows' "reads negative" toggles
+    "static_profile": "ui.fallback",      # built from the price fields
+    "price_taxes_profile": "ui.region",   # a preset writes it, "own" keeps it
+}
+# Option keys the page never shows and never writes: passed through as stored.
+HIDDEN: dict = {}
+
+
+def fields():
+    """Every field once, in page order, roster fields after `inverters`."""
+    for group in GROUPS:
+        for part in group.parts:
+            for field in part.fields:
+                yield group, part, field
+                if field.control == INVERTER_LIST:
+                    for sub in ROSTER_FIELDS:
+                        yield group, part, sub
+
+
+def field(key: str) -> Field | None:
+    return next((f for _g, _p, f in fields() if f.key == key), None)
+
+
+def visible(fld: Field, model: dict) -> bool:
+    """Whether `fld` is shown for this page model (uimodel.options_to_ui)."""
+    for name, op, value in fld.show:
+        have = model.get(name)
+        if op == "==" and have != value:
+            return False
+        if op == "!=" and have == value:
+            return False
+        if op == "in" and have not in value:
+            return False
+        try:
+            if op == ">" and not float(have) > value:
+                return False
+            if op == "<" and not float(have) < value:
+                return False
+        except (TypeError, ValueError):
+            return False
+    return True
+
+
+def range_of(key: str, schema_ui: list):
+    """(min, max) from the Supervisor's schema (`info["schema"]`), or None.
+
+    Never typed here: config.yaml is the one place a range is written. A range
+    arrives as lengthMin/lengthMax (tools/supervisor_selfapi_probe.py)."""
+    path = key.split(".")
+    nodes = schema_ui or []
+    for step in path[:-1]:
+        parent = next((n for n in nodes if n.get("name") == step), None)
+        nodes = (parent or {}).get("schema") or []
+    node = next((n for n in nodes if n.get("name") == path[-1]), None)
+    if not node or "lengthMin" not in node or "lengthMax" not in node:
+        return None
+    return node["lengthMin"], node["lengthMax"]

goodwe_controller/app/uimodel.py

@@ -0,0 +1,350 @@
+"""UX-13: stored options <-> the page model, for the keys the page derives.
+
+`options_to_ui()` turns the stored blob into what the page edits: always a list
+of inverter cards, solar rows with a "reads negative" toggle, a contract and
+simple prices instead of `static_profile` JSON, and a region preset instead of
+the levies figure. `ui_to_options()` turns it back, so the validator and the
+Supervisor always see the real blob.
+
+The rule that makes the round trip exact: the model carries the stored values
+of the derived keys (`keep`). A derivation whose page fields still read what
+`keep` decodes to writes `keep` back untouched, and only an edited one is
+re-encoded. So a blob the page cannot express (a `static_profile` with odd
+windows, a malformed roster) survives a save of some other field unchanged.
+See DECISIONS/UX-13-one-layout-table.md.
+"""
+
+import copy
+import json
+
+from .price import FLEMISH_TAXES_COMPONENTS_EUR_KWH
+from .static_tariff import ProfileInvalid, parse_static_profile
+
+__all__ = ["options_to_ui", "ui_to_options", "REGION_PRESETS",
+           "arbitrage_from_batteries", "DeriveError", "COUNT", "GROWN"]
+
+
+class DeriveError(ValueError):
+    """The page model asks for something no options blob can say. `code` names
+    the sentence the page shows (app/ui_text `derive.<code>`), and `field` the
+    page field it is shown beside."""
+
+    def __init__(self, text, code="", field=""):
+        super().__init__(text)
+        self.code, self.field = code, field
+
+
+# The page model's inverter count, which show conditions read, and what adding
+# a card sets: a second inverter turns the one flat inverter into a list.
+COUNT = "inverter_count"
+GROWN = {"inverter_shape": "list"}
+
+
+# --------------------------------------------------------------------------- #
+# Region presets for "Grid costs, levies and VAT". Year-stamped, updated each
+# January (owner, 2026-09-27). Only presets with a sourced figure are listed:
+# Flanders is app/price.py's Fluvius Antwerpen sum (TARIFF-18: Eneco
+# residential card, Flanders, September 2026, VAT included). Wallonia and
+# Brussels have a day and a night band (config.yaml) and join with sourced
+# figures; until then those sites choose "own".
+# --------------------------------------------------------------------------- #
+REGION_PRESETS = {
+    "flanders": {
+        "year": 2026,
+        "taxes_eur_kwh": round(sum(v for _n, v in
+                                   FLEMISH_TAXES_COMPONENTS_EUR_KWH), 5),
+        "taxes_profile": "",
+    },
+}
+OWN = "own"
+
+_ROSTER_FLAT = ("setpoint_entity", "soc_entity", "batt_entity", "batt_invert",
+                "max_w", "bms_soc_floor")
+_TOL = 1e-9
+
+
+def _blank(v) -> bool:
+    return v is None or (isinstance(v, str) and not v.strip())
+
+
+def _num(v):
+    try:
+        return None if _blank(v) or isinstance(v, bool) else float(v)
+    except (TypeError, ValueError):
+        return None
+
+
+# --- 1. one inverter (flat keys) or the `inverters` list -------------------- #
+def _roster_decode(o):
+    entries = o.get("inverters")
+    if entries is None or entries == "" or entries == []:
+        card = {k: o.get(k) for k in _ROSTER_FLAT}
+        card.update(name="", capacity_kwh=None)
+        return {"inverter_shape": "flat", "inverters": [card]}
+    if isinstance(entries, list) and all(isinstance(e, dict) for e in entries):
+        return {"inverter_shape": "list",
+                "inverters": [dict(e) for e in entries]}
+    # Not something a card can show: edited in the Configuration tab only.
+    return {"inverter_shape": "raw", "inverters": None}
+
+
+def _roster_encode(m, keep):
+    out = {}
+    shape, cards = m.get("inverter_shape"), m.get("inverters")
+    if shape == "raw":
+        raise DeriveError("the inverter list is edited in the Configuration tab",
+                          "raw_roster", "inverters")
+    if not cards:
+        raise DeriveError("at least one inverter is needed", "no_inverter",
+                          "inverters")
+    if shape == "flat" and len(cards) == 1:
+        card = cards[0]
+        if not _blank(card.get("name")) or not _blank(card.get("capacity_kwh")):
+            raise DeriveError("one inverter stored flat has no name or "
+                              "capacity", "flat_named", "inverters")
+        for k in _ROSTER_FLAT:
+            if card.get(k) is not None or k in keep:
+                out[k] = card.get(k)
+        out["inverters"] = []
+        return out
+    out["inverters"] = [{k: v for k, v in c.items() if v is not None}
+                        for c in cards]
+    # The flat keys beside a list are not read: they stay as stored.
+    out.update({k: copy.deepcopy(keep[k]) for k in _ROSTER_FLAT if k in keep})
+    if shape == "flat" or _roster_decode(keep)["inverter_shape"] == "flat":
+        # CFG-04 rule 9e: a flat power request entity beside a list is refused,
+        # so a list that replaces the flat inverter clears it.
+        out["setpoint_entity"] = ""
+    return out
+
+
+# --- 2. solar rows: pv_entity / pv_entities / pv_invert_entities ------------ #
+def _strs(v):
+    return [str(x).strip() for x in (v if isinstance(v, list) else [])
+            if not _blank(x)]
+
+
+def _solar_rows(o):
+    listed = _strs(o.get("pv_entities"))
+    if listed:
+        return listed, True
+    one = "" if _blank(o.get("pv_entity")) else str(o.get("pv_entity")).strip()
+    return ([one] if one else []), False
+
+
+def _solar_decode(o):
+    rows, _listed = _solar_rows(o)
+    flipped = set(_strs(o.get("pv_invert_entities")))
+    return {"ui.solar": [{"entity": e, "reversed": e in flipped}
+                         for e in rows]}
+
+
+def _solar_encode(m, keep):
+    out = {}
+    rows = [r for r in (m.get("ui.solar") or [])
+            if not _blank(r.get("entity"))]
+    entities = [str(r["entity"]).strip() for r in rows]
+    old_rows, was_list = _solar_rows(keep)
+    if len(entities) <= 1 and not was_list:
+        out["pv_entity"] = entities[0] if entities else ""
+        if "pv_entities" in keep:
+            out["pv_entities"] = []
+    else:
+        out["pv_entities"] = entities
+        if "pv_entity" in keep:
+            out["pv_entity"] = ""       # TEL-12: the list replaces it
+    # Flips of entities that were never a row stay as stored (pv.stray_inverts
+    # reports them). Flips of removed rows go with the row.
+    extras = [x for x in _strs(keep.get("pv_invert_entities"))
+              if x not in old_rows and x not in entities]
+    flips = [e for e, r in zip(entities, rows) if r.get("reversed")] + extras
+    if flips or "pv_invert_entities" in keep:
+        out["pv_invert_entities"] = flips
+    return out
+
+
+# --- 3. contract and static_profile ----------------------------------------- #
+def _fixed_json(price) -> str:
+    return json.dumps({"periods": [
+        {"name": "all", "from": "00:00", "to": "24:00", "days": "mon-sun",
+         "eur_per_kwh": price}]})
+
+
+def _daynight_json(day, night) -> str:
+    return json.dumps({"periods": [
+        {"name": "day", "from": "07:00", "to": "22:00", "days": "mon-fri",
+         "eur_per_kwh": day},
+        {"name": "night", "from": "22:00", "to": "07:00", "days": "mon-fri",
+         "eur_per_kwh": night},
+        {"name": "night", "from": "00:00", "to": "24:00", "days": "sat,sun",
+         "eur_per_kwh": night}]})
+
+
+def _shape(text):
+    """The periods of a profile without their names, for comparing, or None."""
+    try:
+        prof = parse_static_profile(text)
+    except ProfileInvalid:
+        return None
+    if prof is None:
+        return ()
+    return tuple(sorted((p.start_min, p.end_min, tuple(sorted(p.days)),
+                         p.eur_per_kwh) for p in prof.periods))
+
+
+def _profile_decode(raw):
+    """("none"|"fixed"|"daynight"|"custom", fixed, day, night)."""
+    if isinstance(raw, str) and _blank(raw):
+        return "none", None, None, None
+    if not isinstance(raw, str):
+        return "custom", None, None, None
+    got = _shape(raw)
+    if not got:
+        return ("none" if got == () else "custom"), None, None, None
+    if len(got) == 1 and got == _shape(_fixed_json(got[0][3])):
+        return "fixed", got[0][3], None, None
+    day = next((p[3] for p in got if p[:2] == (420, 1320)), None)
+    night = next((p[3] for p in got if p[:2] == (1320, 420)), None)
+    if (day is not None and night is not None
+            and got == _shape(_daynight_json(day, night))):
+        return "daynight", None, day, night
+    return "custom", None, None, None
+
+
+def _tariff_decode(o):
+    kind, fixed, day, night = _profile_decode(o.get("static_profile", ""))
+    provider = o.get("price_provider")
+    dynamic = not _blank(provider) and provider != "off"
+    return {"ui.contract": "dynamic" if dynamic else kind,
+            "price_provider": provider, "ui.fallback": kind,
+            "ui.fixed_price": fixed, "ui.day_price": day,
+            "ui.night_price": night}
+
+
+def _tariff_encode(m, keep):
+    out = {}
+    contract = m.get("ui.contract")
+    if contract == "dynamic":
+        if _blank(m.get("price_provider")) or m.get("price_provider") == "off":
+            raise DeriveError("a dynamic contract needs a price source",
+                              "no_source", "price_provider")
+        out["price_provider"] = m["price_provider"]
+        kind = m.get("ui.fallback")
+    else:
+        out["price_provider"] = "off"
+        kind = contract
+    if kind == "none":
+        out["static_profile"] = ""
+    elif kind == "fixed":
+        out["static_profile"] = _fixed_json(_price_of(m, "ui.fixed_price"))
+    elif kind == "daynight":
+        out["static_profile"] = _daynight_json(_price_of(m, "ui.day_price"),
+                                               _price_of(m, "ui.night_price"))
+    elif kind == "custom":
+        if "static_profile" not in keep:
+            raise DeriveError("odd tariff windows are edited in the "
+                              "Configuration tab", "custom_profile",
+                              "ui.contract")
+        out["static_profile"] = keep["static_profile"]
+    else:
+        raise DeriveError(f"unknown contract {kind!r}", "unknown",
+                          "ui.contract")
+    return out
+
+
+def _price_of(m, name):
+    value = _num(m.get(name))
+    if value is None:
+        raise DeriveError(f"{name} needs a price", "no_price", name)
+    return value
+
+
+# --- 4. region preset -> price_taxes_eur_kwh / price_taxes_profile ---------- #
+def _region_decode(o):
+    taxes, profile = o.get("price_taxes_eur_kwh"), o.get("price_taxes_profile", "")
+    region = OWN
+    for rid, p in REGION_PRESETS.items():
+        same = _num(taxes) is not None and abs(_num(taxes) - p["taxes_eur_kwh"]) < _TOL
+        if same and str(profile or "").strip() == p["taxes_profile"]:
+            region = rid
+    return {"ui.region": region, "price_taxes_eur_kwh": taxes}
+
+
+def _region_encode(m, keep):
+    region = m.get("ui.region")
+    if region == OWN:
+        out = {"price_taxes_eur_kwh": m.get("price_taxes_eur_kwh")}
+        if "price_taxes_profile" in keep:       # "own" keeps the stored table
+            out["price_taxes_profile"] = keep["price_taxes_profile"]
+        return out
+    if region not in REGION_PRESETS:
+        raise DeriveError(f"unknown region {region!r}", "unknown", "ui.region")
+    p = REGION_PRESETS[region]
+    out = {"price_taxes_eur_kwh": p["taxes_eur_kwh"]}
+    if p["taxes_profile"] or "price_taxes_profile" in keep:
+        out["price_taxes_profile"] = p["taxes_profile"]
+    return out
+
+
+# --- 5. arbitrage_enabled: the OPT-11 hook ---------------------------------- #
+def arbitrage_from_batteries(m):
+    """OPT-11 hook. With battery modes on, `arbitrage_enabled` is true when any
+    battery may sell. Battery modes are not built yet, so this returns None and
+    the toggle is stored as the page has it: no behaviour change."""
+    return None
+
+
+def _arbitrage_decode(o):
+    return {"arbitrage_enabled": o.get("arbitrage_enabled")}
+
+
+def _arbitrage_encode(m, keep):
+    derived = arbitrage_from_batteries(m)
+    value = m.get("arbitrage_enabled") if derived is None else derived
+    return {} if value is None and "arbitrage_enabled" not in keep \
+        else {"arbitrage_enabled": value}
+
+
+# (option keys it writes, decode, encode). Each is independent of the others.
+DERIVATIONS = (
+    (("inverters",) + _ROSTER_FLAT, _roster_decode, _roster_encode),
+    (("pv_entity", "pv_entities", "pv_invert_entities"), _solar_decode,
+     _solar_encode),
+    (("price_provider", "static_profile"), _tariff_decode, _tariff_encode),
+    (("price_taxes_eur_kwh", "price_taxes_profile"), _region_decode,
+     _region_encode),
+    (("arbitrage_enabled",), _arbitrage_decode, _arbitrage_encode),
+)
+_OWNED = {k for keys, _d, _e in DERIVATIONS for k in keys}
+_MODEL_ONLY = ("keep", "inverter_shape", "inverter_count", "region_year")
+
+
+def options_to_ui(options: dict) -> dict:
+    """The page model for a stored blob. Pure: reads nothing else."""
+    model = {k: copy.deepcopy(v) for k, v in options.items()
+             if k not in _OWNED}
+    for _keys, decode, _encode in DERIVATIONS:
+        model.update(decode(options))
+    model["keep"] = {k: copy.deepcopy(options[k]) for k in _OWNED
+                     if k in options}
+    cards = model.get("inverters")
+    model["inverter_count"] = len(cards) if isinstance(cards, list) else None
+    preset = REGION_PRESETS.get(model["ui.region"])
+    model["region_year"] = preset["year"] if preset else None
+    return model
+
+
+def ui_to_options(model: dict) -> dict:
+    """The options blob for a page model. Raises DeriveError on a model no blob
+    can express, so the page says so instead of saving something else."""
+    keep = model.get("keep") or {}
+    out = {k: copy.deepcopy(v) for k, v in model.items()
+           if k not in _MODEL_ONLY and k not in _OWNED
+           and not k.startswith("ui.")}
+    for keys, decode, encode in DERIVATIONS:
+        was = decode(keep)
+        if all(model.get(name) == value for name, value in was.items()):
+            out.update({k: copy.deepcopy(keep[k]) for k in keys if k in keep})
+        else:
+            out.update(encode(model, keep))
+    return out

goodwe_controller/app/uipage.py

@@ -0,0 +1,357 @@
+"""UX-13 P2: the settings view's server half. It names no option key.
+
+It turns app/uilayout.py's table into the JSON the page draws from (labels
+from the Supervisor's translations, ranges and choices from its schema, page
+words from app/ui_text), turns a posted page model into options through
+app/uimodel.py, and says beside which page field each validator sentence
+goes. The rules stay in validate.py and the sentences are passed on as they
+are (DECISIONS/UX-13-one-layout-table.md).
+"""
+
+import copy
+import io
+import json
+import os
+import re
+
+from . import uilayout as L
+from . import uimodel as U
+from .configui import help_of, label_of, problems_by_field, split_group
+from .validate import power_request_entities
+
+UI_TEXT = os.path.join(os.path.dirname(os.path.abspath(__file__)), "ui_text",
+                       "en.json")
+# A choice the page cannot make, only keep: odd tariff windows (P5 editor).
+ONLY_IF_HELD = ("custom",)
+_TIERS = ("bad", "warn", "info")
+
+
+def ui_text() -> dict:
+    with io.open(UI_TEXT, encoding="utf-8") as f:
+        return json.load(f)
+
+
+def _roster():
+    """The inverter list field's key, read off the table."""
+    return next(f.key for _g, _p, f in L.fields()
+                if f.control == L.INVERTER_LIST)
+
+
+def _node(schema_ui, key):
+    """The Supervisor's schema entry for `key` (`list.sub` too), or {}."""
+    nodes, path = schema_ui or [], key.split(".")
+    for step in path[:-1]:
+        parent = next((n for n in nodes if n.get("name") == step), None)
+        nodes = (parent or {}).get("schema") or []
+    return next((n for n in nodes if n.get("name") == path[-1]), None) or {}
+
+
+def _words(translations, lang, key, T):
+    """(label, help) for a field: ui_text for `ui.` fields, else the
+    translation without its `Group · ` prefix, and the raw key last."""
+    if key.startswith("ui."):
+        entry = T["fields"].get(key[3:], {})
+        return entry.get("name", key), entry.get("description", "")
+    path = tuple(key.split(".")[:-1])
+    name = key.split(".")[-1]
+    label, _lang = label_of(translations, lang, name, path)
+    text, _lang = help_of(translations, lang, name, path)
+    return split_group(label)[1], text
+
+
+def _choices(fld, node, T, value_type):
+    """[[value, label, only_if_held], ...] for a choice control, or None."""
+    if fld.control not in (L.SEGMENTED, L.SELECT, L.CHOICE):
+        return None
+    name = fld.key[3:] if fld.key.startswith("ui.") else fld.key
+    words = T["choices"].get(name) or {}
+    if fld.key.startswith("ui."):
+        values = list(words)
+    elif node.get("options"):
+        values = [v for v in node["options"] if not words or v in words]
+    elif value_type == "integer" and node.get("lengthMax") is not None:
+        values = list(range(int(node["lengthMin"]), int(node["lengthMax"]) + 1))
+        if words:
+            values = [v for v in values if str(v) in words]
+    else:
+        return []
+    out = []
+    for v in values:
+        label = words.get(str(v))
+        if label is None:
+            label = (T["settings"]["hour"].replace("{hour}", f"{v:02d}")
+                     if isinstance(v, int) else str(v))
+        preset = U.REGION_PRESETS.get(v) if fld.fills else None
+        if preset:
+            label = f"{label}, " + T["settings"]["region_year"].replace(
+                "{year}", str(preset["year"]))
+        out.append([v, label, v in ONLY_IF_HELD])
+    return out
+
+
+def _field(fld, schema_ui, translations, lang, T):
+    node = _node(schema_ui, fld.key)
+    label, text = _words(translations, lang, fld.key, T)
+    if fld.unit:
+        # The page shows the unit beside the control, in its own scale (kW),
+        # so the translation's "(W)" goes; "(optional)" stays.
+        label = re.sub(r"\s*\([^()\s]{1,6}\)", "", label)
+    value_type = ("float" if fld.control == L.NUMBER and fld.key.startswith("ui.")
+                  else node.get("type") or "")
+    out = {"key": fld.key, "control": fld.control, "label": label,
+           "help": text, "unit": fld.unit, "scale": fld.scale,
+           "step": fld.step, "kind": fld.kind,
+           "show": [list(c) for c in fld.show], "applies": fld.applies,
+           "wizard": fld.wizard,
+           "type": value_type, "optional": not node.get("required", False),
+           # A choice mirrored into a field also shows (and finds) its keys.
+           "writes": sorted(k for k, how in L.DERIVED.items()
+                            if how in (fld.key, fld.mirror))}
+    if node.get("lengthMin") is not None:
+        out["min"] = node["lengthMin"]
+    if node.get("lengthMax") is not None:
+        out["max"] = node["lengthMax"]
+    choices = _choices(fld, node, T, value_type)
+    if choices is not None:
+        out["choices"] = choices
+        name = fld.key[3:] if fld.key.startswith("ui.") else fld.key
+        later = T.get("choices_later", {}).get(name)
+        if later:
+            out["later"] = [[v, words] for v, words in later.items()]
+        hints = T.get("choice_help", {}).get(name)
+        if hints:
+            out["hints"] = {v: e.get("description", "")
+                            for v, e in hints.items()}
+    if fld.mirror:
+        out["mirror"] = fld.mirror
+    if fld.fills:
+        out["fills"] = fld.fills
+        out["presets"] = {rid: {"year": p["year"], "value": p["taxes_eur_kwh"]}
+                          for rid, p in U.REGION_PRESETS.items()}
+    roster = _roster()
+    if fld.key.startswith(roster + "."):
+        sub = fld.key[len(roster) + 1:]
+        if L.DERIVED.get(sub) == roster:
+            out["flat"] = sub           # how the one flat inverter stores it
+    if fld.control == L.INVERTER_LIST:
+        out["fields"] = [_field(sub, schema_ui, translations, lang, T)
+                         for sub in L.ROSTER_FIELDS]
+        out["count"] = U.COUNT
+        out["grow"] = dict(U.GROWN)
+        out["shape"] = next(iter(U.GROWN))
+    return out
+
+
+def layout(schema_ui, translations, lang="en") -> dict:
+    """Every group, part and field of the Installer view, as the page draws
+    it. Built from the table only: a field the table places is on the page."""
+    T = ui_text()
+    groups = []
+    for g in L.GROUPS:
+        parts = []
+        for p in g.parts:
+            words = T["parts"].get(f"{g.id}.{p.id}", {}) if p.id else {}
+            parts.append({"id": p.id, "name": words.get("name", ""),
+                          "description": words.get("description", ""),
+                          "collapsed": p.collapsed,
+                          "fields": [_field(f, schema_ui, translations, lang, T)
+                                     for f in p.fields]})
+        words = T["groups"].get(g.id, {})
+        applies = sorted({f.applies for p in g.parts for f in p.fields})
+        groups.append({"id": g.id, "name": words.get("name", g.id),
+                       "description": words.get("description", ""),
+                       "support_only": g.support_only,
+                       "applies": [T["applies"][a]["name"] for a in applies],
+                       "parts": parts})
+    return {"groups": groups}
+
+
+# --------------------------------------------------------------------------- #
+# The page model -> options, for the validator and the save
+# --------------------------------------------------------------------------- #
+def _same(a, b) -> bool:
+    """Equal as the Supervisor stores it: 3 and 3.0 alike, True and 1 not."""
+    if isinstance(a, bool) or isinstance(b, bool):
+        return type(a) is type(b) and a == b
+    if isinstance(a, (int, float)) and isinstance(b, (int, float)):
+        return a == b
+    if isinstance(a, list) and isinstance(b, list):
+        return len(a) == len(b) and all(_same(x, y) for x, y in zip(a, b))
+    if isinstance(a, dict) and isinstance(b, dict):
+        return a.keys() == b.keys() and all(_same(a[k], b[k]) for k in a)
+    return type(a) is type(b) and a == b
+
+
+def to_options(model: dict, stored: dict | None = None) -> dict:
+    """The options blob for a posted page model. A value equal to the stored
+    one is written as stored, in the stored key order, so a save that changed
+    nothing writes an identical blob (the browser reads 3.0 as 3)."""
+    out = U.ui_to_options(model)
+    stored = stored or {}
+    for k, v in out.items():
+        if k in stored and _same(v, stored[k]):
+            out[k] = copy.deepcopy(stored[k])
+    return ({k: out[k] for k in stored if k in out}
+            | {k: v for k, v in out.items() if k not in stored})
+
+
+def derive_message(err: U.DeriveError) -> dict:
+    words = ui_text()["settings"]["derive"]
+    text = words.get(err.code, words["unknown"])["description"]
+    return {"field": err.field or None, "card": None, "tier": "bad",
+            "text": text}
+
+
+# --------------------------------------------------------------------------- #
+# Where a sentence goes on the page
+# --------------------------------------------------------------------------- #
+# `inverters.max_w`, or `inverters[1].setpoint_entity` for one card.
+_SUB = re.compile(r"(?<![A-Za-z0-9_])([a-z_0-9]+)(?:\[(\d+)\])?\.([a-z_0-9]+)")
+
+
+def _mirror_of(key):
+    return next((f.key for _g, _p, f in L.fields() if f.mirror == key), None)
+
+
+def targets(key: str, text: str, model: dict) -> list:
+    """[(page field, card)] for a sentence that names option `key`. `card` is
+    the inverter card's index, or None."""
+    roster = _roster()
+    cards = model.get(roster) if isinstance(model.get(roster), list) else []
+    names = [c.get("name") for c in cards if isinstance(c, dict)]
+    # messages.setting(): “Inverter rating” for inverter-b (inverters.max_w),
+    # or a roster rule's own `inverters[1] (inverter-b)`.
+    card = next((i for i, n in enumerate(names)
+                 if n and f"for {n} ({roster}." in text), None)
+    index = re.search(re.escape(roster) + r"\[(\d+)\]", text)
+    if card is None and index and int(index.group(1)) < len(cards):
+        card = int(index.group(1))
+    if key == roster:
+        subs = [(f"{roster}.{s}", int(i) if i and int(i) < len(cards) else card)
+                for r, i, s in _SUB.findall(text) if r == roster]
+        subs = [x for x in dict.fromkeys(subs) if L.field(x[0])]
+        return subs or [(roster, card)]
+    if key in L.DERIVED:
+        how = L.DERIVED[key]
+        if how == roster:
+            return [(f"{roster}.{key}", 0 if card is None else card)]
+        fld = L.field(how)
+        if fld is not None and not L.visible(fld, model) and _mirror_of(how):
+            return [(_mirror_of(how), None)]
+        return [(how, None)]
+    if L.field(key) is not None:
+        return [(key, None)]
+    return [(None, None)]
+
+
+def anchors(problems, notes, model, keys) -> list:
+    """[{field, card, tier, text}] for the refusals and notes. `field` is
+    None for a sentence that names no setting on the page."""
+    out, seen = [], set()
+
+    def add(field, card, tier, text):
+        if (field, card, text) not in seen:
+            seen.add((field, card, text))
+            out.append({"field": field, "card": card, "tier": tier,
+                        "text": text})
+
+    by_key, unanchored = problems_by_field(problems, keys)
+    for key, texts in by_key.items():
+        for text in texts:
+            for field, card in targets(key, text, model):
+                add(field, card, "bad", text)
+    for text in unanchored:
+        add(None, None, "bad", text)
+    for note in notes:
+        tier = note.tier if note.tier in _TIERS else "info"
+        for key in note.keys or (None,):
+            for field, card in (targets(key, note.text, model) if key
+                                else [(None, None)]):
+                add(field, card, tier, note.text)
+    # A sentence placed on one inverter's field is not also put on the list.
+    roster = _roster()
+    placed = {m["text"] for m in out
+              if (m["field"] or "").startswith(roster + ".")}
+    return [m for m in out if not (m["field"] == roster
+                                   and m["text"] in placed)]
+
+
+def fields_of(keys, model) -> list:
+    """The page fields that show these option keys (a stale save's list)."""
+    return list(dict.fromkeys(f for k in keys for f, _c in targets(k, "", model)
+                              if f))
+
+
+# --------------------------------------------------------------------------- #
+# UX-13 P4: the setup wizard (DECISIONS/UX-13-setup-wizard.md)
+# --------------------------------------------------------------------------- #
+# Store keys (app/store.py), not options. SETUP_DONE is written when the
+# wizard saves. STARTED is the one control's Start and Stop write.
+SETUP_DONE = "setup_done"
+STARTED = "auto"
+
+
+def setup_needed(stored: dict, store_data, started, fresh=False) -> str | None:
+    """Why the page opens the wizard by itself, or None.
+
+    "no_power_request": the stored options name no inverter to control, so
+    the add-on cannot start on them. "first_start": a new install. This boot
+    found no Store file (`fresh`), the wizard never saved and control was never
+    started or stopped. `fresh` is what tells a new install from an old site
+    that was never started, e.g. one left in shadow for weeks (TEST-23).
+    `store_data` is the Store's dict (None: unknown, so no), `started` is
+    whether control is started now."""
+    if not power_request_entities(stored or {}):
+        return "no_power_request"
+    if store_data is None or not fresh:
+        return None
+    if store_data.get(SETUP_DONE) or STARTED in store_data or started:
+        return None
+    return "first_start"
+
+
+def setup_spec() -> dict:
+    """What the wizard needs beyond each field's step: read off the table."""
+    kettle = {}
+    for source, (read, outcomes) in L.KETTLE.items():
+        kettle[source] = {"read": [[f, sign] for f, sign in read]}
+        for way, (say, sets) in outcomes.items():
+            kettle[source][way] = {"say": say, "sets": sets}
+    field, on, off = L.SHADOW
+    return {"steps": L.WIZARD_STEPS, "final": L.FINAL_STEP,
+            "optional": list(L.OPTIONAL_STEPS),
+            "kettle": {"source": L.KETTLE_SOURCE, "min_w": L.KETTLE_MIN_W,
+                       "sources": kettle},
+            "shadow": {"field": field, "on": on, "off": off}}
+
+
+def kettle(source, before_w, after_w):
+    """The kettle test's verdict, as the page reaches it (settings.js
+    `kettleOutcome`): (outcome, fields it sets or None, change in W), or None
+    for a source the page cannot read."""
+    spec = L.KETTLE.get(source)
+    if spec is None:
+        return None
+    change = float(after_w) - float(before_w)
+    if abs(change) < L.KETTLE_MIN_W:
+        return "none", None, change
+    say, sets = spec[1]["up" if change > 0 else "down"]
+    return say, (dict(sets) if sets is not None else None), change
+
+
+def step_of(field_key, model) -> int:
+    """The wizard step a sentence on this page field blocks: the field's own
+    step while it is shown, else the last step, which lists everything."""
+    fld = L.field(field_key) if field_key else None
+    if fld is None or not fld.wizard or not L.visible(fld, model):
+        return L.FINAL_STEP
+    return fld.wizard
+
+
+def step_problems(messages, model) -> dict:
+    """{"1": n, ...}: how many refusals block each wizard step."""
+    out = {str(n): 0 for n in range(1, L.WIZARD_STEPS + 1)}
+    for m in messages:
+        if m.get("tier") == "bad":
+            out[str(step_of(m.get("field"), model))] += 1
+    return out

goodwe_controller/app/watchdog.py

@@ -670,11 +670,10 @@ class SignWatchdog:
         # ⚠️ `self.against` IS THE ONLY THING SAFETY-30 CHANGED IN THIS STRING,
         # and it defaults to the wording that shipped - "a meter reading" - so a
         # one-inverter install's `reason` is byte-identical to what an operator
-        # (and test_watchdog.py) has always read. A per-unit instance names what
-        # it actually compared instead, because "commanded +1500 W against a
-        # meter reading -1500 W" would be a false statement about which
-        # instrument produced the evidence, on the one line somebody woken by
-        # this alarm reads first.
+        # has always read (test_watchdog.py pins its meaning). A per-unit
+        # instance names what it actually compared instead, because "commanded
+        # +1500 W against a meter reading -1500 W" would be a false statement
+        # about which instrument produced the evidence.
         self.reason = (
             f"SIGN_DISAGREEMENT: commanded {commanded_w:+.0f} W against "
             f"{self.against} {against_w:+.0f} W for {held:.0f} s continuously "

goodwe_controller/app/web.py

@@ -10,7 +10,9 @@ a cellar, by someone who did not write it. Numbers alone are not enough - it
 says what is wrong in words.
 
 ⚠️ SINCE UX-02 THERE ARE TWO PAGES HERE, AND ONLY ONE OF THEM IS THIS FILE'S.
-`/` is the status and control surface and is unchanged. `/config` is the
+`/` is the status and control surface; since UX-13 P1 its files are in
+app/static/ and its Home screen reads the structured half of `/status`
+(app/homeview.py). `/config` is the
 configuration surface: its markup lives in app/config_page.py, its field model
 in app/configui.py and its Supervisor conversation in app/selfconfig.py. What
 stays HERE is the routing, so that the question a reviewer has to answer - does
@@ -24,97 +26,60 @@ routes below read `GET /addons/self/info`, run the SHIPPED validator, write
 mode or reaches `controller.handle_action()`. The set of things an operator can
 do to the inverter through this panel is exactly what `/action` offered before
 this card - test_selfconfig.py part 7 asserts that by listing the routes and the
-actions and comparing them with the shipped set.
+actions and comparing them with the shipped set. UX-13's `ha/entities` is a GET
+of Home Assistant's entity list (app/haentities.py) and writes nothing.
+UX-13 P4's setup wizard uses the same routes. The one thing it adds that is
+not options is a Store key, `setup_done`, written when the wizard's save
+succeeds, so the page stops opening the wizard by itself (uipage.setup_needed).
 """
 
+import io
+import json
 import logging
+import os
+from datetime import datetime, timezone
 
 from aiohttp import web
 
-from . import selfconfig
+from . import messages, selfconfig, uipage
+from .haentities import EntityCache
+from .homeview import region_of
+from .validate import config_notes, setup_checks
 from .config_page import CONFIG_PAGE
 from .configui import changed_keys, field_model, problems_by_field
+from .uimodel import DeriveError, options_to_ui
 
 _LOG = logging.getLogger("goodwe.web")
 
-PAGE = """<!doctype html>
-<html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
-<title>GoodWe RS485 Controller</title>
-<style>
- :root{--bg:#f5f6f8;--card:#fff;--ink:#1c1e21;--muted:#6b7280;--line:#e5e7eb;
-       --ok:#137333;--warn:#b25e02;--bad:#c5221f}
- @media(prefers-color-scheme:dark){:root{--bg:#111317;--card:#1b1e24;--ink:#e8eaed;
-       --muted:#9aa0a6;--line:#2c3038;--ok:#81c995;--warn:#fdd663;--bad:#f28b82}}
- *{box-sizing:border-box}
- body{margin:0;padding:16px;background:var(--bg);color:var(--ink);
-      font:15px/1.5 system-ui,-apple-system,Segoe UI,Roboto,sans-serif}
- h1{font-size:18px;margin:0 0 12px}
- .card{background:var(--card);border:1px solid var(--line);border-radius:10px;
-       padding:14px;margin-bottom:12px}
- .banner{font-weight:600;padding:12px 14px;border-radius:10px;margin-bottom:12px}
- .b-ok{background:rgba(19,115,51,.12);color:var(--ok)}
- .b-warn{background:rgba(178,94,2,.12);color:var(--warn)}
- .b-bad{background:rgba(197,34,31,.12);color:var(--bad)}
- table{width:100%;border-collapse:collapse}
- td{padding:6px 0;border-bottom:1px solid var(--line);vertical-align:top}
- td:last-child{text-align:right;font-variant-numeric:tabular-nums;font-weight:600}
- tr:last-child td{border-bottom:0}
- .k{color:var(--muted);font-weight:400}
- ul{margin:6px 0 0;padding-left:18px}
- li{margin:3px 0}
- .ok{color:var(--ok)} .bad{color:var(--bad)} .warn{color:var(--warn)}
- button{font:inherit;padding:9px 14px;border-radius:8px;border:1px solid var(--line);
-        background:var(--card);color:var(--ink);cursor:pointer;margin:0 6px 6px 0}
- button.primary{background:#1a73e8;border-color:#1a73e8;color:#fff}
- button.danger{background:var(--bad);border-color:var(--bad);color:#fff}
- .muted{color:var(--muted);font-size:13px}
-</style></head><body>
-<h1>GoodWe RS485 Controller</h1>
-<p class="muted"><a href="config">Configuration &rarr;</a></p>
-<div id="banner" class="banner b-warn">loading…</div>
+# UX-13 P1: the page lives in app/static/ as three files - index.html,
+# app.css, app.js - plus the page words from app/ui_text/en.json. They are
+# joined into ONE response here, once, so the page needs no second request
+# and no route of its own: the route list below is unchanged, and every URL
+# the page uses stays relative (ingress). No build step, no external file.
+STATIC = os.path.join(os.path.dirname(os.path.abspath(__file__)), "static")
+UI_TEXT = os.path.join(os.path.dirname(os.path.abspath(__file__)), "ui_text",
+                       "en.json")
 
-<div class="card">
-  <table id="live"></table>
-</div>
 
-<div class="card">
-  <div class="k">Commissioning</div>
-  <ul id="checks"></ul>
-</div>
+def _read(path):
+    with io.open(path, encoding="utf-8") as f:
+        return f.read()
 
-<div class="card">
-  <button class="primary" onclick="act('auto_toggle')">Start / stop control</button>
-  <button onclick="act('maint_start')">Force maintenance cycle</button>
-  <button class="danger" onclick="act('maint_abort')">Abort maintenance</button>
-  <div class="muted" id="hint"></div>
-</div>
 
-<script>
-async function refresh(){
-  try{
-    const r = await fetch('status', {cache:'no-store'});
-    const s = await r.json();
-    const b = document.getElementById('banner');
-    b.textContent = s.banner;
-    b.className = 'banner ' + (s.level==='ok'?'b-ok':s.level==='bad'?'b-bad':'b-warn');
-    document.getElementById('live').innerHTML = s.rows
-      .map(([k,v]) => `<tr><td class="k">${k}</td><td>${v}</td></tr>`).join('');
-    document.getElementById('checks').innerHTML = s.checks
-      .map(c => `<li class="${c.ok?'ok':(c.warn?'warn':'bad')}">${c.ok?'✓':(c.warn?'!':'✗')} ${c.text}</li>`)
-      .join('');
-    document.getElementById('hint').textContent = s.hint || '';
-  }catch(e){
-    document.getElementById('banner').textContent = 'cannot reach the add-on';
-  }
-}
-async function act(what){
-  await fetch('action', {method:'POST', headers:{'Content-Type':'application/json'},
-                         body: JSON.stringify({action: what})});
-  refresh();
-}
-refresh(); setInterval(refresh, 3000);
-</script></body></html>
-"""
+def page() -> str:
+    """The assembled index page. `</` is escaped inside the two inline
+    scripts, so no text in them can close the tag early."""
+    ui_text = json.dumps(json.loads(_read(UI_TEXT)), ensure_ascii=False)
+    scripts = {}
+    for name in ("app.js", "settings.js"):
+        scripts[name] = _read(os.path.join(STATIC, name))
+        if "</script" in scripts[name].lower():
+            raise ValueError(f"{name} may not contain a closing script tag")
+    return (_read(os.path.join(STATIC, "index.html"))
+            .replace("/*APP_CSS*/", _read(os.path.join(STATIC, "app.css")))
+            .replace("/*UI_TEXT*/", ui_text.replace("</", "<\\/"))
+            .replace("/*APP_JS*/", scripts["app.js"])
+            .replace("/*SETTINGS_JS*/", scripts["settings.js"]))
 
 
 # ⚠️ WHAT THE PANEL SAYS WHEN IT COULD NOT READ A DEVICE RANGE. Two of
@@ -125,11 +90,8 @@ refresh(); setInterval(refresh, 3000);
 # them too, and says so, because a green page that is green for a reason the
 # operator cannot see is the exact failure this add-on keeps refusing to ship.
 DEVICE_NOTE = (
-    "%s did not report a range, so the two checks that compare a configured "
-    "ceiling against what the device itself accepts were skipped - here and at "
-    "startup, identically. Everything else was checked. If the device answers "
-    "later and disagrees, the add-on refuses to start then, with the same "
-    "message you would have seen here.")
+    "%s did not report its power range, so two checks were skipped, here and "
+    "at start. If they fail later, the add-on will not start then.")
 
 
 def build_app(controller, selfcfg=None) -> web.Application:
@@ -143,9 +105,27 @@ def build_app(controller, selfcfg=None) -> web.Application:
     if selfcfg is None:
         selfcfg = selfconfig.SelfConfig(controller.hass.session,
                                         controller.hass.token)
+    entities = EntityCache(controller.hass)
+    index_page = page()
+    # UX-13 P4: the blobs /config/model handed out, by fingerprint, so a stale
+    # save can name only the keys that moved underneath the page (finding a).
+    handed: dict = {}
+
+    def hand_out(options):
+        fp = selfconfig.fingerprint(options)
+        handed.pop(fp, None)
+        handed[fp] = options
+        while len(handed) > 16:
+            handed.pop(next(iter(handed)))
+        return fp
+
+    def store_data():
+        store = getattr(controller, "store", None)
+        data = getattr(store, "data", None)
+        return data if isinstance(data, dict) else None
 
     async def index(_request):
-        return web.Response(text=PAGE, content_type="text/html")
+        return web.Response(text=index_page, content_type="text/html")
 
     async def status(_request):
         return web.json_response(controller.status_payload())
@@ -165,15 +145,22 @@ def build_app(controller, selfcfg=None) -> web.Application:
     async def config_index(_request):
         return web.Response(text=CONFIG_PAGE, content_type="text/html")
 
-    async def _proposed(request):
+    async def _proposed(request, stored=None):
+        """(body, options, model). UX-13's settings view posts its page
+        `model`, which app/uimodel.py turns into the options blob here, so the
+        validator and the Supervisor only ever see a real blob. The classic
+        page posts `options`. Raises DeriveError for a model no blob can say."""
         try:
             body = await request.json()
         except ValueError:
             raise web.HTTPBadRequest(text="expected JSON")
+        model = body.get("model")
+        if isinstance(model, dict):
+            return body, uipage.to_options(model, stored), model
         options = body.get("options")
         if not isinstance(options, dict):
             raise web.HTTPBadRequest(text="expected an options object")
-        return body, options
+        return body, options, None
 
     async def config_model(request):
         """Everything the page needs to draw itself, from ONE Supervisor call.
@@ -198,10 +185,23 @@ def build_app(controller, selfcfg=None) -> web.Application:
                             info.get("translations") or {}, lang)
         model.update({
             "options": options,
-            "fingerprint": selfconfig.fingerprint(options),
+            "fingerprint": hand_out(options),
             "running": controller.o,
             "running_differs": changed_keys(controller.o, options),
             "lang": lang,
+            # UX-13 P1: the levies preset and its year, for the P2 Settings
+            # screens, which show the year beside the region choice.
+            "region": region_of(options),
+            # UX-13 P2: the Installer view draws from these two.
+            "layout": uipage.layout(info.get("schema") or [],
+                                    info.get("translations") or {}, lang),
+            "ui": options_to_ui(options),
+            # UX-13 P4: the setup wizard, and why it opens by itself.
+            "setup": uipage.setup_spec(),
+            "setup_needed": uipage.setup_needed(
+                options, store_data(), bool(getattr(controller, "auto", False)),
+                fresh=getattr(getattr(controller, "store", None), "fresh",
+                              False) is True),
         })
         return web.json_response(model)
 
@@ -218,16 +218,48 @@ def build_app(controller, selfcfg=None) -> web.Application:
         product this card is delivering; anything this layer did to them would
         be a second opinion about a rule it does not own.
         """
-        _body, options = await _proposed(request)
+        try:
+            _body, options, model = await _proposed(request)
+        except DeriveError as err:
+            return web.json_response({"problems": [], "by_key": {},
+                                      "unanchored": [], "notes": [],
+                                      "messages": [uipage.derive_message(err)]})
+        notes = []
         problems, unread = await selfconfig.problems_and_ranges(
-            options, controller.hass)
+            options, controller.hass, notes=notes)
         by_key, unanchored = problems_by_field(problems, _keys_of(options))
+        # UX-13: warnings and info beside the refusals. Never block a save.
+        # The entity checks use the picker's cached list and never wait on HA.
+        notes += config_notes(options, entities=entities.peek())
         payload = {"problems": problems, "by_key": by_key,
-                   "unanchored": unanchored}
+                   "unanchored": unanchored,
+                   "notes": [n._asdict() for n in notes]}
         if unread:
             payload["device_note"] = DEVICE_NOTE % ", ".join(sorted(set(unread)))
+        if model is not None:
+            payload["messages"] = uipage.anchors(problems, notes, model,
+                                                 _keys_of(options))
+            payload["steps"] = uipage.step_problems(payload["messages"], model)
+        if _body.get("setup"):
+            payload["setup"] = [n._asdict() for n in await _setup_checks(options)]
         return web.json_response(payload)
 
+    async def _setup_checks(options):
+        """The wizard's live checks: a list at most a few seconds old, and
+        what the running add-on already knows (its meter, today's prices)."""
+        rows, age = await entities.get(max_age=5.0)
+        if age is not None and age >= 30.0:
+            rows = None             # Home Assistant is not answering
+        try:
+            prices = (controller.status_payload().get("plan") or {}).get(
+                "prices") or []
+            known = sum(1 for p in prices if p.get("eur_kwh") is not None)
+        except Exception:  # noqa: BLE001 - a display figure, never a failure
+            known = None
+        return setup_checks(options, entities=rows, running=controller.o,
+                            meter_now_w=getattr(controller, "grid", None),
+                            prices_known=known)
+
     def _keys_of(options):
         # ⚠️ THE ANCHOR LIST IS THE KEYS OF THE BLOB UNDER TEST, and that is
         # sound only because the page posts the WHOLE blob it read - which is
@@ -238,33 +270,73 @@ def build_app(controller, selfcfg=None) -> web.Application:
 
     async def config_save(request):
         """Validate, compare-and-swap, write. Or refuse and write NOTHING."""
-        body, options = await _proposed(request)
+        # The page model carries no stored values of the keys it shows, so the
+        # blob is settled against what is stored: an unchanged value is written
+        # exactly as stored (uipage.to_options).
+        try:
+            posted = await request.json()
+        except ValueError:
+            raise web.HTTPBadRequest(text="expected JSON")
+        stored_now = None
+        if isinstance(posted, dict) and isinstance(posted.get("model"), dict):
+            try:
+                stored_now = (await selfcfg.info()).get("options") or {}
+            except selfconfig.SupervisorUnavailable as err:
+                _LOG.error("saving options failed: %s", err)
+                return web.json_response({"error": str(err)}, status=502)
+        try:
+            body, options, model = await _proposed(request, stored_now)
+        except DeriveError as err:
+            return web.json_response(
+                {"kind": "invalid", "problems": [], "by_key": {},
+                 "unanchored": [], "messages": [uipage.derive_message(err)]},
+                status=422)
         expect = str(body.get("fingerprint") or "")
         try:
             result = await selfconfig.save(selfcfg, options, expect,
-                                           hass=controller.hass)
+                                           hass=controller.hass,
+                                           base=handed.get(expect))
         except selfconfig.SaveRefused as refused:
             if refused.kind == "stale":
                 stored = refused.stored or {}
+                # The fields to look at are the ones the OTHER surface moved,
+                # not this page's own edits (UX-13 P2 test, finding a).
+                moved = (refused.changed if refused.moved is None
+                         else refused.moved)
                 return web.json_response(
                     {"kind": "stale", "changed": refused.changed,
+                     "moved": refused.moved,
+                     "changed_fields": (uipage.fields_of(moved, model)
+                                        if model is not None else []),
                      "stored": stored,
                      # The page needs the CURRENT token to be able to save
                      # again after the operator has read the difference. That
                      # is not a force door: it takes a second, deliberate press
                      # made in front of what changed.
-                     "fingerprint": selfconfig.fingerprint(stored)},
+                     "fingerprint": hand_out(stored)},
                     status=409)
             by_key, unanchored = problems_by_field(refused.problems,
                                                    _keys_of(options))
-            return web.json_response(
-                {"kind": "invalid", "problems": refused.problems,
-                 "by_key": by_key, "unanchored": unanchored}, status=422)
+            payload = {"kind": "invalid", "problems": refused.problems,
+                       "by_key": by_key, "unanchored": unanchored}
+            if model is not None:
+                payload["messages"] = uipage.anchors(refused.problems, [],
+                                                     model, _keys_of(options))
+                payload["steps"] = uipage.step_problems(payload["messages"],
+                                                        model)
+            return web.json_response(payload, status=422)
         except selfconfig.SupervisorUnavailable as err:
             _LOG.error("saving options failed: %s", err)
             return web.json_response({"error": str(err)}, status=502)
         controller.log_event("configuration saved from the panel - "
-                             "not applied until the add-on restarts")
+                             "not applied until the add-on restarts",
+                             hint=messages.hint("settings_saved"))
+        # `handed` keeps `expect`: another page may have opened the same blob.
+        store = getattr(controller, "store", None)
+        if (model is not None and body.get("setup") == "done"
+                and store is not None):
+            store.set(uipage.SETUP_DONE,
+                      datetime.now(timezone.utc).isoformat(timespec="seconds"))
         return web.json_response({"ok": True, **result})
 
     async def config_restart(request):
@@ -288,9 +360,20 @@ def build_app(controller, selfcfg=None) -> web.Application:
         except selfconfig.SupervisorUnavailable as err:
             _LOG.error("restart request failed: %s", err)
             return web.json_response({"error": str(err)}, status=502)
-        controller.log_event("restart requested from the configuration panel")
+        controller.log_event("restart requested from the configuration panel",
+                             hint=messages.hint("restart_requested"))
         return web.json_response({"ok": True})
 
+    async def ha_entities(request):
+        """UX-13: Home Assistant's entities for the picker. A read only, and
+        never an error: when Home Assistant is down the list says so."""
+        kind = str(request.query.get("kind", "") or "")[:16]
+        one = str(request.query.get("entity", "") or "")[:255]
+        if one:
+            # UX-13 P4's kettle test: one entity, read now.
+            return web.json_response(await entities.reading(one))
+        return web.json_response(await entities.payload(kind))
+
     app = web.Application()
     app.add_routes([
         web.get("/", index),
@@ -301,12 +384,21 @@ def build_app(controller, selfcfg=None) -> web.Application:
         web.post("/config/validate", config_validate),
         web.post("/config/save", config_save),
         web.post("/config/restart", config_restart),
+        web.get("/ha/entities", ha_entities),
     ])
     return app
 
 
+def access_log():
+    """UX-10: the page polls /status every few seconds, and aiohttp logs each
+    request at INFO. That access log is kept for a DEBUG log level only."""
+    return (logging.getLogger("aiohttp.access")
+            if _LOG.isEnabledFor(logging.DEBUG) else None)
+
+
 async def start(controller, port: int = 8099, selfcfg=None):
-    runner = web.AppRunner(build_app(controller, selfcfg))
+    runner = web.AppRunner(build_app(controller, selfcfg),
+                           access_log=access_log())
     await runner.setup()
     site = web.TCPSite(runner, "0.0.0.0", port)
     await site.start()

goodwe_controller/config.yaml

@@ -1,5 +1,5 @@
 name: GoodWe RS485 Controller
-version: "0.9.0"
+version: "0.12.0"
 slug: goodwe_controller
 description: >-
   Drives a GoodWe ES/BP battery inverter over RS485 by emulating its smart
@@ -93,7 +93,7 @@ options:
   # against a sibling's numbers; an entry silently inheriting `soc_entity` would
   # rebuild that defect in YAML. `name`, `setpoint_entity`, `max_w` and
   # `bms_soc_floor` are therefore REQUIRED of every entry (the schema below enforces it, and
-  # validate.py rule 9 enforces it again for the callers the Supervisor never
+  # validate.py rules 8 and 9 enforce it again for the callers the Supervisor never
   # sees). An omitted `soc_entity`/`batt_entity` means THIS UNIT HAS NO SUCH
   # SENSOR - `inputs_ok` already stops the site for that - and never means
   # "use the other one's".
@@ -147,6 +147,76 @@ options:
   inverters: []
   estop_fitted: false
 
+  # TEL-11 - THE SITE'S PV PRODUCTION, IN WATTS, AND IT IS READ BY NOTHING THAT
+  # DECIDES ANYTHING. Optional, empty on every install that does not set it, and
+  # when it is empty the add-on reads no entity, announces no entity, publishes
+  # no topic and shows no status row.
+  #
+  # ⚠️ AN HA ENTITY AND NOT A REGISTER, BECAUSE MOST SOLAR INVERTERS ARE NOT ON
+  # THIS BUS. The RS485 bus this add-on speaks carries the BATTERY inverter it
+  # drives; a household's PV inverter is normally a different box from a
+  # different vendor, reporting into Home Assistant through its own integration.
+  # So this takes whatever `sensor.*` the site's PV integration provides, any
+  # brand Home Assistant can read.
+  #
+  # POSITIVE IS PRODUCTION. An entity that reads the other way round goes in
+  # `pv_invert_entities` below - see DECISIONS/TEL-14-pv-sign.md.
+  #
+  # ⚠️ THE ENTITY'S OWN `unit_of_measurement` IS WHAT IS BELIEVED - W, kW, MW
+  # and the rest of Home Assistant's power units. A sensor with no unit, or with
+  # a unit that is not power, is REFUSED and the status page says which: there
+  # is no magnitude heuristic that can tell 30 W of dusk from 30 kW of noon, and
+  # a factor of 1000 in the one channel that exists to be believed a week later
+  # is worse than a refusal an operator can read.
+  pv_entity: ""
+
+  # TEL-12 - THE SAME CHANNEL WHEN THE ROOF HAS SEVERAL INVERTERS, WHICH IS THE
+  # ORDINARY CASE AND NOT AN EDGE ONE. A multi-string or multi-orientation roof
+  # routinely carries two or three PV inverters, each publishing its own power
+  # sensor; 0.11.0 shipped `pv_entity` as a single string and the reference
+  # site's owner reported within minutes that they could configure one of
+  # theirs. List them all here and the row carries the SITE total.
+  #
+  # ⚠️ DECLARED, THIS REPLACES `pv_entity` - it does not extend it. Set both and
+  # ONLY this list is read, and the status page says so. That is CFG-04's rule
+  # for `inverters:` applied to the upgrade path this key exists for: the
+  # install being upgraded HAS `pv_entity` set, and an operator who adds all
+  # their inverters to this list while the old key still names one of them would
+  # DOUBLE that inverter under a union rule. Clear `pv_entity` when you fill
+  # this in.
+  #
+  # ⚠️ AND IF ANY ONE OF THEM IS NOT REPORTING, THERE IS NO SITE TOTAL - the row
+  # publishes `unknown` and the recorder records a GAP. It does NOT publish the
+  # sum of the ones that answered: two of three inverters add up to a smaller
+  # number that is indistinguishable from a real one, and a week later that
+  # reads as "there was less sun than there was" - the exact conclusion this
+  # channel exists to TEST rather than to manufacture. The status page names
+  # which entity is missing and why, and lists what the others reported, because
+  # a human reading it live wants the diagnostic; the recorded number does not,
+  # because nobody re-derives a week of history. See
+  # DECISIONS/TEL-12-several-pv-inverters.md.
+  #
+  # ⚠️ THE FIX IS NOT A TEMPLATE SENSOR THAT SUMS THEM. You may legitimately
+  # prefer one, but a template sensor summing an `unavailable` source yields the
+  # partial total silently - the same defect one layer down, in a place this
+  # add-on cannot see or report.
+  #
+  #   pv_entities:
+  #     - sensor.pv_east_power
+  #     - sensor.pv_west_power
+  #     - sensor.pv_garage_power
+  #
+  # Each entity's OWN `unit_of_measurement` is read, so a kW inverter beside a W
+  # one sums correctly. Empty is the shipped default and means "use `pv_entity`,
+  # which is also empty" - i.e. no PV channel at all, which is every install.
+  pv_entities: []
+
+  # TEL-14. Every PV entity listed here (in `pv_entity` or `pv_entities`) has
+  # its sign flipped, for a kWh meter or power clamp that reads production as
+  # negative. Per entity, because one roster can mix both conventions. `[]` is
+  # load-bearing like `pv_entities: []`; see DECISIONS/TEL-14-pv-sign.md.
+  pv_invert_entities: []
+
   # ==========================================================================
   # METER - where the grid reading comes from
   # ==========================================================================
@@ -156,7 +226,7 @@ options:
   # ha_signed reads ONE signed HA entity (+ import / - export), which is what a
   # HomeWizard P1 publishes and what ha_dsmr cannot consume.
   # homewizard_local skips Home Assistant entirely and polls the meter's own
-  # local API. ⚠️ It is the ONLY mode whose sensor.p1_sample_age_s measures when
+  # local API. ⚠️ It is the ONLY mode whose sensor.goodwe_p1_sample_age measures when
   # the meter REPORTED rather than when the value last CHANGED - HA emits
   # nothing at all for a repeated reading - so it is the only mode a firmware
   # watchdog may threshold. See DOCS.md.
@@ -291,13 +361,58 @@ options:
   # price_markup_eur_kwh is ignored under it, with a line in the log saying so.
   price_provider: "off"
   price_markup_eur_kwh: 0.03
-  price_taxes_eur_kwh: 0.06
+
+  # TARIFF-18. The all-in Flemish non-energy figure, EUR/kWh, incl. 6 % VAT.
+  # Its components are named in app/price.py's FLEMISH_TAXES_COMPONENTS_EUR_KWH
+  # and test_price.py section 1b re-adds them:
+  #
+  #   Fluvius distribution (Antwerpen)              5,35  c EUR/kWh
+  #   Bijzondere accijns, "Alle verbruik"           4,876
+  #   Bijdrage groene stroom en WKK Vlaanderen      1,51
+  #   Energiebijdrage (0 EUR/MWh since 2026-08-01)  0
+  #                                                ------
+  #                                                11,736 c EUR/kWh = 0.11736
+  #
+  # ⚠️ THIS IS PER-DSO AND YOURS IS PROBABLY DIFFERENT. Only the distribution
+  # row moves: across the eight Fluvius DSOs it runs 5,28 c EUR/kWh
+  # (Midden-Vlaanderen) to 6,70 (West), so the Flemish total runs about 0.117
+  # to 0.131. Antwerpen is near the LOW end, which is the direction this
+  # default should err in - it is inert on which hour is cheapest, but §17's
+  # negative-price guard reads the ABSOLUTE all-in price, and a figure set too
+  # high would carry a genuinely negative hour above zero.
+  #
+  # ⚠️ WALLONIA AND BRUSSELS DO NOT BELONG IN THIS SCALAR AT ALL. Their
+  # distribution tariff has a day and a night band; use price_taxes_profile.
+  price_taxes_eur_kwh: 0.11736
 
   # §9.3: injection is priced SEPARATELY, and in Belgium it is often near zero -
-  # which by itself strongly favours self-consumption over export. A scalar, not
-  # a second series: no shipped supplier publishes a dynamic injection curve.
+  # which by itself strongly favours self-consumption over export. This is the
+  # FLAT injection price, for a site paid the same for every exported kWh.
+  #
+  # ⚠️ THE REASON THIS COMMENT USED TO GIVE - "no shipped supplier publishes a
+  # dynamic injection curve" - WAS FALSE, and TARIFF-07 struck the same
+  # sentence from app/price.py and DOCS.md without reaching this file. Eneco
+  # publishes `0,1 x BELPEX-H - 1,188` c EUR/kWh on the same card as its
+  # consumption formula, ENGIE publishes `(B x eSpot_15) - A`, and Aspiravi
+  # `0,07 x Belpex - 2`. A site on one of those sets price_export_formula
+  # below; this scalar stays the fixed-product default and is what every site
+  # uses today.
   export_price_eur_kwh: 0.04
 
+  # TARIFF-16. The INJECTION leg as a formula, in price_formula's own grammar
+  # and with its OWN coefficients: Eneco uses 0,102 on consumption and 0,100 on
+  # injection, and injection is VAT-EXEMPT where consumption is at 6%, so
+  # `vat_pct` here is normally 0. A negative `offset` is expected - it is what
+  # the published lines carry - and the resulting price legitimately goes below
+  # zero in the midday hours a PV household exports in.
+  #
+  # ⚠️ NO STRATEGY IN THIS ADD-ON READS IT. arbitrage.py prices the sell side
+  # as displaced IMPORT and compares two all-in CONSUMPTION prices; it does not
+  # read the injection price at all. This option is what the operator is shown
+  # and the shape a future export-aware strategy would rest on. Empty by
+  # default, which leaves every existing site on the scalar above.
+  price_export_formula: ""
+
   # §14's `tariffs.static_profile`, and "" is its `null`. §9.2: "a large share
   # of the installed base is on [a static profile]" - this is what makes those
   # sites first-class rather than "price_provider: off, good luck".
@@ -328,6 +443,43 @@ options:
   # validate.py warns about exactly that.
   static_profile: ""
 
+  # TARIFF-17. THE TAXES COMPONENT AS A DAY/NIGHT TABLE, for the sites whose
+  # network tariff actually has one. "" means the flat price_taxes_eur_kwh
+  # above decides, which is what every install has had until now and is CORRECT
+  # IN FLANDERS: Fluvius distribution is a single rate, and its row on the
+  # tariff card offers only `Normaal | Uitsl. nacht` - exclusive night being a
+  # separate physical circuit, not the night register of a dual-rate meter.
+  #
+  # The Walloon and Brussels DSOs are on the same card with FOUR columns -
+  # `Enkelvoudig | Dag | Nacht | Uitsl. nacht` - and the gap is real money
+  # (c EUR/kWh): ORES dag 13,27 / nacht 7,39; AIESH 15,17 / 8,21; Tecteo RESA
+  # 12,20 / 7,01; Sibelga 9,39 / 7,10; ORES IMPACT 2026 16,578 / 5,090.
+  #
+  # ⚠️ WHY THIS IS NOT COSMETIC. The optimiser reads the SPREAD (max - min) and
+  # which hour is cheapest. A flat number is additive and identical every hour,
+  # so it cancels out of both - it cannot distort anything, and it also cannot
+  # express this. These bands are ANTI-CORRELATED with what the battery wants
+  # to do (cheap network hours are cheap spot hours), so flattening them
+  # UNDERSTATES the true spread and declines cycles that would have paid. See
+  # DOCS.md, "The three buckets".
+  #
+  # Same JSON grammar as static_profile above - the same tiling rule, the same
+  # day selectors, the same DST handling, because it is literally the same
+  # parser. ⚠️ THE VALUE IS THE TAXES COMPONENT ALONE, NOT AN ALL-IN PRICE:
+  #
+  #   {"periods": [
+  #      {"name":"dag",  "from":"07:00","to":"22:00","days":"mon-fri","eur_per_kwh":0.1327},
+  #      {"name":"nacht","from":"22:00","to":"07:00","days":"mon-fri","eur_per_kwh":0.0739},
+  #      {"name":"nacht","from":"00:00","to":"24:00","days":"sat,sun", "eur_per_kwh":0.0739}]}
+  #
+  # ⚠️ SET THIS *OR* price_taxes_eur_kwh, NOT BOTH. Two writers of one quantity,
+  # one of which silently wins, is refused at startup: leave the scalar at its
+  # shipped default when you fill this in. A scalar still sitting on the
+  # SUPERSEDED 0.06 is accepted too (TARIFF-18 moved that default, and your
+  # stored options carry the old number whether you typed it or not) - the
+  # refusal is about a figure you chose, not about one this add-on wrote.
+  price_taxes_profile: ""
+
   # TARIFF-15. YOUR OWN TARIFF CARD, as two fixed coefficients. Used only when
   # `price_provider: custom_formula`; "" is unset.
   #
@@ -664,6 +816,38 @@ options:
   # and not 150 or 200. 37 control cycles.
   delivery_hold_s: 185
 
+  # SAFETY-10. Run the whole decision path and command NOTHING - strategies,
+  # arbiter, clamps and guards all run, the decision and its reason are
+  # recorded, and every inverter is held at 0 W. `app/shadow.py` carries the
+  # argument; the three things to know before changing this line are:
+  #
+  #   auto  shadow WHILE CONTROL IS STOPPED, live once it is started. This is
+  #         the shipped value and it is what "default-on" means here.
+  #   on    always shadow, whatever the Start / stop button says. This is the
+  #         one an operator picks to watch a day of decisions on an armed site
+  #         before letting it trade.
+  #   off   ordinary control.
+  #
+  # ⚠️ IT IS NOT A BOOLEAN DEFAULTING TO `true`, AND THAT IS THE WHOLE CARD.
+  # The Supervisor composes an add-on's options as `{**these defaults, **the
+  # stored user options}`, so a NEW key with a new default reaches every
+  # EXISTING install on the next update - including one regulating a real
+  # battery. `shadow_mode: true` would silently stop it, and the only symptom
+  # would be a battery that has stopped doing anything. There is no mechanism
+  # in this options system that lets one key default differently for a new
+  # install and an existing one, so "default-on for new" has to be a value the
+  # add-on RESOLVES. `auto` is that value: a fresh install ships
+  # `auto_start: false` and therefore comes up in shadow mode; an install that
+  # is controlling is started, so `auto` resolves to live and NOTHING about it
+  # changes.
+  #
+  # ⚠️ AND UNDER `auto` THE START BUTTON LEAVES SHADOW MODE. Pressing *Start /
+  # stop control* is the operator saying "control the battery". Somebody who
+  # wants the decisions recorded WHILE the loop runs sets `on` explicitly -
+  # which is the configuration this option exists for, and the one that cannot
+  # be reached by accident.
+  shadow_mode: "auto"
+
   # ==========================================================================
   # ADVANCED - the control law and diagnostics
   # ==========================================================================
@@ -734,12 +918,13 @@ schema:
   # batteries, whereas an absent capacity has an honest answer - no opinion
   # about the split, every unit weighs 1.0, which is what shipped.
   #
-  # ⚠️ THREE KEYS ARE REQUIRED PER ENTRY AND THAT IS DELIBERATE. An entry with
+  # ⚠️ FOUR KEYS ARE REQUIRED PER ENTRY AND THAT IS DELIBERATE. An entry with
   # no `name` has no Store namespace and would share another unit's SAFETY-02
   # latch; one with no `setpoint_entity` is a unit nothing can command; one with
   # no `max_w` would have to borrow a rating, which is the sibling-grading
-  # defect DEV-02 removed. The optional pair is the sensors, whose absence
-  # honestly means "this unit reports none".
+  # defect DEV-02 removed; `bms_soc_floor` is SAFETY-32's (options block above).
+  # The optional keys are the sensors, whose absence honestly means "this unit
+  # reports none", and `capacity_kwh`.
   #
   # ⚠️ THIS BLOCK IS DECLARED BEFORE `max_w:` ON PURPOSE. `max_w` now appears
   # TWICE under `schema:` - once nested here, once flat below - and a reader
@@ -758,6 +943,41 @@ schema:
       capacity_kwh: float(0.1,200)?
 
   estop_fitted: bool
+  # TEL-11. Optional, and OPTIONAL WITHOUT A COMPANION RULE - unlike
+  # `price_now_entity`/`price_avg_entity`, which are legal only while
+  # `price_provider` is `off` and make the add-on REFUSE TO START otherwise.
+  # Nothing in validate.py mentions this key: it cannot conflict with anything,
+  # because nothing else reads it.
+  pv_entity: str?
+
+  # TEL-12. ⚠️ A SECOND KEY RATHER THAN A LIST SHAPE ON `pv_entity`, AND THAT IS
+  # A MEASUREMENT AND NOT A PREFERENCE. `pv_entity` shipped in 0.11.0 as `str?`
+  # and the reference site has a string persisted in it. Declared as a list,
+  # Supervisor 2026.08.0 answers that stored string with
+  #
+  #   Invalid list for option 'pv_entity' in GoodWe RS485 Controller
+  #
+  # and `deepmerge`'s list strategy is `override`, so a shipped `[]` default does
+  # NOT rescue it - the operator's string stands and is refused. That is CFG-04
+  # §B's trap in the other direction: an add-on that will not start, and the
+  # schema needed to fix it pinned to the version that cannot be installed. The
+  # only single-key spelling Supervisor accepts for BOTH shapes is `match(.*)?`,
+  # which validates nothing at all (it admits a number, a dict, any list of
+  # anything) and renders as a plain text box. Measured, both of them, by
+  # `tools/supervisor_shape_probe.py` §G - the transcript is in
+  # DECISIONS/TEL-12-several-pv-inverters.md §1.
+  #
+  # ⚠️ AND `pv_entities: []` IN THE `options:` BLOCK IS LOAD-BEARING, exactly as
+  # `inverters: []` is. §G measures the same isolated counterfactual: the
+  # shipped defaults MINUS only this key are refused with `Missing option
+  # 'pv_entities' in root`, which is every options blob written before 0.12.
+  # `p1_phase_import_entities` is the shipped precedent for the pair.
+  pv_entities:
+    - str
+  # TEL-14. A parallel list, not a prefix or a dict: measured by
+  # tools/supervisor_shape_probe.py section H, DECISIONS/TEL-14-pv-sign.md.
+  pv_invert_entities:
+    - str
 
   # ==========================================================================
   # METER - where the grid reading comes from
@@ -842,11 +1062,24 @@ schema:
   # bottoms out at 0 would make that site inexpressible.
   export_price_eur_kwh: float(-1,1)
 
+  # TARIFF-16. A JSON string in `price_formula`'s grammar, parsed by
+  # `custom_formula.parse_export_formula()` - the SAME parser with its option
+  # name as an argument, so a second unit table and a second card rule do not
+  # exist to diverge. The `card` block is OPTIONAL on this leg and required on
+  # the other: Eneco prints its injection formula with no price beside it, so
+  # on that card there is nothing to grade against, and the add-on says at
+  # startup that the leg is ungraded rather than inventing an estimate.
+  price_export_formula: str?
+
   # A JSON string rather than a nested schema, deliberately: it is ONE option
   # key (§14 has one), it survives config.yaml's flat options block, and
   # parse_static_profile() accepts an already-parsed dict too, so a future
   # nested schema is a config.yaml change and no code change at all.
   static_profile: str?
+  # TARIFF-17. A JSON string for `static_profile`'s reason, and parsed by
+  # `static_tariff.parse_taxes_profile()` - the SAME period grammar, so a
+  # second tiling rule and a second set of DST bugs do not exist to diverge.
+  price_taxes_profile: str?
   # TARIFF-15. A JSON string for the same reason `static_profile` is one: it is
   # ONE option key, it survives config.yaml's flat options block, and
   # parse_price_formula() accepts an already-parsed dict too, so a future
@@ -970,6 +1203,15 @@ schema:
   # running short of one unit's share must be reported well inside one.
   delivery_hold_s: int(30,900)
 
+  # SAFETY-10. ⚠️ A THREE-VALUED LIST AND NOT A `bool`, for the reason written
+  # against the default in the options block above: a boolean has one default
+  # and the Supervisor gives it to every install, new and existing alike.
+  # `app/shadow.MODES` is this tuple and `validate.py` rule 11 refuses anything
+  # else BY NAME, because `shadow.mode()` resolves an unreadable value to
+  # SHADOW - safe, but a silent reinterpretation that commands nothing for as
+  # long as nobody notices.
+  shadow_mode: list(auto|on|off)
+
   # ==========================================================================
   # ADVANCED - the control law and diagnostics
   # ==========================================================================

goodwe_controller/named_absence.py

@@ -0,0 +1,99 @@
+"""Read a value a check prints or grades without raising (TEST-26).
+
+Each test file is one script, so an IndexError in a print or a check name
+kills every check after it (MUTATION.md, FCST-06). Read through these instead,
+and conjoin `present(x)` in the check so the absence grades as a named FAIL.
+
+`ABSENT` values never raise: they format as `<ABSENT ...>` under any spec,
+index and attribute to themselves, compare unequal AND not-unequal, and are
+falsy. `not x`, `"a" not in x` and `all(... for _ in x)` are therefore TRUE of
+one, which is why the check needs the `present()` term. `int()`, `range()` and
+use as a list index still raise: guard those with `present()`.
+"""
+
+_NAN = float("nan")
+
+
+class Absent:
+    __slots__ = ("what",)
+
+    def __init__(self, what):
+        object.__setattr__(self, "what", what)
+
+    def __repr__(self):
+        return f"<ABSENT {self.what}>"
+
+    __str__ = __repr__
+
+    def __format__(self, spec):
+        return repr(self)
+
+    def __bool__(self):
+        return False
+
+    def __eq__(self, other):
+        return False
+
+    __ne__ = __lt__ = __le__ = __gt__ = __ge__ = __eq__
+
+    def __hash__(self):
+        return id(self)
+
+    def __getitem__(self, _):
+        return self
+
+    def __getattr__(self, _):
+        return self
+
+    def __call__(self, *_a, **_k):
+        return self
+
+    def __len__(self):
+        return 0
+
+    def __iter__(self):
+        return iter(())
+
+    def __contains__(self, _):
+        return False
+
+    def __float__(self):
+        return _NAN
+
+    def _same(self, *_):
+        return self
+
+    __add__ = __radd__ = __sub__ = __rsub__ = __mul__ = __rmul__ = _same
+    __truediv__ = __rtruediv__ = __floordiv__ = __rfloordiv__ = _same
+    __mod__ = __rmod__ = __neg__ = __pos__ = __abs__ = __round__ = _same
+
+
+def present(*xs):
+    """True when none of `xs` is an ABSENT stand-in."""
+    return not any(isinstance(x, Absent) for x in xs)
+
+
+def nth(seq, i=0, what=None):
+    """`seq[i]`, or an ABSENT saying how many items there were."""
+    n = 0 if seq is None else len(seq)
+    if -n <= i < n:
+        return seq[i]
+    return Absent(what or f"[{i}] of {n} item(s)")
+
+
+def first(it, what="no match"):
+    """`next(it)`, or ABSENT when it is exhausted."""
+    return next(iter(it), Absent(what))
+
+
+def field(mapping, key, what=None):
+    """`mapping[key]`, or ABSENT when the key (or the mapping) is missing."""
+    try:
+        return mapping[key]
+    except (KeyError, IndexError, TypeError):
+        return Absent(what or f"key {key!r}")
+
+
+def given(x, what="None"):
+    """`x`, or ABSENT when it is None - so `:.2f` and arithmetic cannot raise."""
+    return Absent(what) if x is None else x