diff --git a/.gitea/workflows/checks.yml b/.gitea/workflows/checks.yml
index 0d4f451..7366a2f 100644
--- a/.gitea/workflows/checks.yml
+++ b/.gitea/workflows/checks.yml
@@ -1,24 +1,15 @@
-# CI-01: this repository's FIRST automated check. Before this file, admin/goodwe-addon
-# had no `.gitea/workflows/` directory at all - eight runnable test files, ~100 s
-# 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.
+# CI-02 PROBE WORKFLOW - THROWAWAY. This branch is deleted after the run.
 #
-# ⚠️ 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
-# must; never the workflow.
+# It replaces the real gate with a set of one-bit steps, because this Gitea
+# 404s its Actions log endpoints and the ONLY machine-readable channel out of a
+# job is /api/v1/repos/.../actions/runs/<id>/jobs, which carries a per-STEP
+# conclusion. So each question this ticket has to answer is asked as its own
+# step, and the answer is read as that step's success or failure.
 #
-# ⚠️ 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
-# rig label without wanting a rig. Nothing below starts, stops, or reads the
-# `goodwe-sim` compose project or takes `sim/riglock.py`; it runs one short
-# container and exits. It does occupy the runner's single slot (`capacity: 1`),
-# so it QUEUES behind a rig campaign - a delayed verdict, never a destroyed one.
-#
-# NO JS ACTIONS: the runner image has no node, so `actions/checkout` cannot run.
-# Checkout is seven lines of git below.
+# There is deliberately NO `concurrency:` block: the point of pushes B and C is
+# to find out whether a still-WAITING run is cancelled by the next push even
+# when the workflow asks for no concurrency at all. If it is, the cancellation
+# is the server's and no edit to this file can prevent it.
 name: checks
 
 on:
@@ -26,111 +17,91 @@ on:
     branches: [release/1.0, master]
   workflow_dispatch:
 
-concurrency:
-  # ⚠️ PER PULL REQUEST, NOT A BARE NAME. A shared group holds one running and
-  # one pending run, so a bare name lets a second PR supersede a first PR's run
-  # before any runner has picked it up - which is exactly what happened to the
-  # other repo's run 521 (four jobs, `started_at` at the Unix epoch,
-  # `runner_id: 0`, concluded `cancelled`, and the PR merged anyway). Do not
-  # replace this with a constant.
-  group: addon-checks-${{ github.event.pull_request.number || github.ref }}
-  cancel-in-progress: true
-
 jobs:
   unit:
     runs-on: [self-hosted, goodwe-rig]
-    timeout-minutes: 70   # ~4 to run; the rest is queueing for the single slot
+    timeout-minutes: 20
     env:
-      # ⚠️ UNDER /home/homelab, NOT $GITHUB_WORKSPACE (ENV-01, and re-measured
-      # during CI-01). act's workspace is `/root/.cache/act/<id>/hostexecutor`, a
-      # path that exists only INSIDE the runner container. Hand it to the host's
-      # snap-confined dockerd and the build fails with "failed to read
-      # dockerfile", or - worse, and this is the documented case - a bind mount
-      # resolves to an EMPTY DIRECTORY with no error at all. /home/homelab is
-      # mirrored 1:1 into the runner and is under $HOME, where snap confinement
-      # accepts it. The same probe under /tmp failed and under $HOME succeeded.
-      WS: /home/homelab/ci/addon-checks-${{ github.run_number }}
+      WS: /home/homelab/ci/ci02probe-${{ github.run_number }}
+      PRNUM: ${{ github.event.pull_request.number }}
+      PRHEAD: ${{ github.event.pull_request.head.sha }}
+      BASEREF: ${{ github.base_ref }}
+      TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      URL: ${{ github.server_url }}/${{ github.repository }}.git
     steps:
-      # ⚠️ THE CHECKOUT IS TWO LEVELS BELOW THE MOUNT ROOT, DELIBERATELY.
-      # test_freeze.py's find_hwsim() reads `HERE.parents[1] / "goodwe" / "sim"`,
-      # looking for the infra repo as a SIBLING of this one. Check out flat -
-      # goodwe_controller directly at the mount root - and `parents[1]` does not
-      # exist, so the test dies on `IndexError: 1` before its first assertion.
-      # Measured during CI-01; the flat layout was tried first and did exactly
-      # that. $WS/goodwe-addon/goodwe_controller gives parents[1] == $WS.
-      - name: checkout into a path the host shares (git; no node for actions/checkout)
-        env:
-          URL: ${{ github.server_url }}/${{ github.repository }}.git
-          TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: P00 an empty clone to ask the server questions from
         run: |
           set -eu
-          rm -rf "$WS" && mkdir -p "$WS/goodwe-addon" && cd "$WS/goodwe-addon"
+          rm -rf "$WS" && mkdir -p "$WS" && cd "$WS"
           git init -q .
           git remote add origin "$(echo "$URL" | sed "s#://#://x-access-token:${TOKEN}@#")"
-          git fetch -q --depth 1 origin "$GITHUB_REF" || git fetch -q --depth 1 origin "$GITHUB_SHA"
-          git checkout -qf FETCH_HEAD
-          echo "checked out $(git log --oneline -1)"
+          echo "GITHUB_REF=$GITHUB_REF"
+          echo "GITHUB_SHA=$GITHUB_SHA"
+          echo "PRNUM=$PRNUM PRHEAD=$PRHEAD BASEREF=$BASEREF"
 
-      - name: build the test image (shipped deps, from apk - see .gitea/ci/Dockerfile)
-        run: |
-          set -eu
-          docker build -q -t goodwe-addon-checks:1 "$WS/goodwe-addon/.gitea/ci" >/dev/null
-          docker run --rm goodwe-addon-checks:1 python3 -c \
-            'import aiohttp, paho.mqtt.client as m, sys; print("python", sys.version.split()[0], "aiohttp", aiohttp.__version__)'
-
-      # ⚠️ THE FILE LIST IS DERIVED FROM THE TREE, NOT TYPED HERE. A hand-written
-      # list is how a new test file joins the repo and is never run - the exact
-      # shape of failure this ticket exists to close. The step globs `test_*.py`,
-      # prints the count, and REFUSES A COUNT OF ZERO: a loop over an empty glob
-      # exits 0 and would report a green gate that examined nothing.
-      #
-      # ⚠️ test_loop.py TAKES ~93 SECONDS OF WALL CLOCK ON PURPOSE (its own
-      # docstring says so, and says why: it drives the real `run_control()`
-      # against a real wall-clock floor, and mocking the clock would leave the
-      # assertion testing the mock). It is not hung. Do not "fix" it with a
-      # shorter timeout - a 60 s limit was tried during CI-01 and reported
-      # exactly the false hang the docstring predicts.
-      #
-      # ⚠️ WHAT THIS RUN DOES NOT COVER, stated because a pass here would
-      # otherwise over-claim. test_freeze.py's third section wants the infra
-      # repo's `sim/hwsim.py` to drive a real HTTP meter through the real
-      # transport. admin/goodwe is PRIVATE (checked via the API) and this
-      # workflow's GITHUB_TOKEN is minted for THIS repository only, so hwsim is
-      # absent here and `find_hwsim()` returns None. The rest of the file runs
-      # and passes. It does so SILENTLY - the file prints nothing to say the
-      # hwsim section was skipped - so "test_freeze.py: PASS" below is a weaker
-      # claim than it looks. That belongs to whoever owns test_freeze.py next;
-      # naming it here is the least this gate can do about it.
-      - name: the add-on's own tests
-        run: |
-          set -eu
-          docker run --rm -v "$WS:/w:ro" goodwe-addon-checks:1 sh -eu -c '
-            cd /w/goodwe-addon/goodwe_controller
-            set -- test_*.py
-            if [ "$1" = "test_*.py" ]; then
-              echo "NO test_*.py FOUND - the mount is empty or the layout moved. NOTHING has been checked."
-              exit 1
-            fi
-            echo "$# test file(s) to run"
-            rc=0
-            for f in "$@"; do
-              start=$(date +%s)
-              if python3 "$f" > /tmp/out 2>&1; then
-                echo "PASS  $f  ($(( $(date +%s) - start ))s)"
-              else
-                echo "FAIL  $f  ($(( $(date +%s) - start ))s)"
-                tail -40 /tmp/out
-                rc=1
-              fi
-            done
-            exit $rc
-          '
-
-      - name: clean up
+      - name: P01 GITHUB_REF is refs-pull-N-head (the bare head)
         if: always()
         run: |
-          rm -rf "$WS" || true
-          # Root-owned by this runner inside a directory the `homelab` user owns,
-          # and sudo on that box is interactive-only, so the user cannot clean
-          # this up and the job that made it has to.
-          ls -1dt /home/homelab/ci/addon-checks-*/ 2>/dev/null | tail -n +6 | xargs -r rm -rf || true
+          set -eu
+          test "$GITHUB_REF" = "refs/pull/$PRNUM/head"
+
+      - name: P02 GITHUB_REF is refs-pull-N-merge (merged content)
+        if: always()
+        run: |
+          set -eu
+          test "$GITHUB_REF" = "refs/pull/$PRNUM/merge"
+
+      - name: P03 GITHUB_SHA equals the PR head sha
+        if: always()
+        run: |
+          set -eu
+          test "$GITHUB_SHA" = "$PRHEAD"
+
+      - name: P04 the first half of the shipped fallback fetches at all
+        if: always()
+        run: |
+          set -eu
+          cd "$WS"
+          git fetch -q --depth 1 origin "$GITHUB_REF"
+
+      - name: P05 ...and what it lands on IS the bare PR head
+        if: always()
+        run: |
+          set -eu
+          cd "$WS"
+          git fetch -q --depth 1 origin "$GITHUB_REF"
+          test "$(git rev-parse FETCH_HEAD)" = "$PRHEAD"
+
+      - name: P06 refs-pull-N-merge exists on the server for an OPEN pr
+        if: always()
+        run: |
+          set -eu
+          cd "$WS"
+          git fetch -q --depth 1 origin "refs/pull/$PRNUM/merge"
+
+      - name: P07 a real merge of this head into the base tip applies cleanly
+        if: always()
+        run: |
+          set -eu
+          cd "$WS"
+          git fetch -q origin "+refs/heads/$BASEREF:refs/remotes/origin/base"
+          git fetch -q origin "+refs/pull/$PRNUM/head:refs/remotes/origin/pr"
+          git checkout -qf refs/remotes/origin/base
+          git -c user.email=ci@local -c user.name=ci merge --no-edit --no-ff refs/remotes/origin/pr
+
+      - name: P08 the base tip is already an ancestor of the head
+        if: always()
+        run: |
+          set -eu
+          cd "$WS"
+          git fetch -q origin "+refs/heads/$BASEREF:refs/remotes/origin/base"
+          git fetch -q origin "+refs/pull/$PRNUM/head:refs/remotes/origin/pr"
+          git merge-base --is-ancestor refs/remotes/origin/base refs/remotes/origin/pr
+
+      - name: P09 hold the single runner slot so the next push has to wait
+        if: always()
+        run: sleep 150
+
+      - name: P99 clean up
+        if: always()
+        run: rm -rf "$WS" || true
diff --git a/goodwe_controller/CHANGELOG.md b/goodwe_controller/CHANGELOG.md
index ef47f8b..9e92b23 100644
--- a/goodwe_controller/CHANGELOG.md
+++ b/goodwe_controller/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+**CI-02 PROBE - THROWAWAY, DO NOT MERGE.** This paragraph exists only to
+collide with the entries release/1.0 has gained since this branch point, so
+that the pull request is genuinely unmergeable and the gate can be observed
+reporting on it. The branch and its pull request are deleted afterwards.
+
 **Thirty days of the real meter, and the acceptance criterion three cards
 deferred is now a number (DATA-01).** TARIFF-01 and SAFETY-07 both merged with
 AC 3 - *"monthly peak held under the soft limit in >= 95 % of intervals over a