SAFETY-32 round 5: stop closing sites, build an instrument that finds its own scope

Rounds 2, 3 and 4 each closed exactly the survivor they were handed and each time
the reviewer found the same shape one step over: the reduction, the call site, the
sibling argument, and now the sibling MODULE. Round 4's enumeration stopped at the
`Controller` class boundary; round 5's four blockers were reductions in validate.py,
over a list DERIVED from the roster three calls away from it. Closing four more sites
by hand would have produced a fifth rejection, so this round widens the instrument
instead and lets it enumerate.

⚠️ THE BLOCKERS ARE NOT EQUIVALENT MUTANTS - a safety refusal disappears, verified by
calling the shipped validator both ways on the real tree:

  roster max_w 5000 (inverter-a) beside 2000 (inverter-b), sign_disagree_w 3000
    clean                        -> 1 problem, "...max_w (inverter-b) is 2000 W, so the
                                    SAFETY-02 sign-disagreement watchdog can never fire"
    min(caps[:1])          +4 B  -> 0 problems. The site STARTS.
    caps_ix[:1]            +4 B  -> 0 problems.
  the SAME roster with the small cap FIRST (2000, 5000)
    clean                        -> 1 problem, naming inverter-a
    min(caps[-1:])         +5 B  -> 0 problems.

⚠️ AND THE ONE-ROSTER FIXTURE COULD NOT HAVE SEEN THAT. On [5000, 2000] the `[-1:]`
mutant still refuses, because last IS min there. A fixture of N members cannot separate
two reductions that agree on N members - which is why the behavioural half below is a
SET and not a roster.

THE INSTRUMENT (test_peakguard.py part 12j, widened past `Controller`)

Every `.py` under app/ is read off disk and parsed - NO MODULE IS NAMED IN THE CHECK -
and the roster is found by transitive closure from ONE seed, the `inverters` option key:
through returns, through lists ACCUMULATED in a loop over a roster (which is exactly
what `caps`, `roster` and `problems` are, and what round 4's rule could not express),
through attributes and properties, and THROUGH CALL ARGUMENTS, which is how it walks
into peakguard, arbiter, allocator, circulation, maintenance and store without being
told they exist. A slice of a roster stays a roster so a mutation cannot cut the taint;
an index is one unit and does not.

  183 roster reductions across 9 modules, out of 23 files parsed:
  main 96, allocator 24, validate 19, arbiter 14, circulation 10, maintenance 10,
  peakguard 4, inverter 3, store 3.  14 modules reduce over no roster at all.

⚠️ THE HAND-WRITTEN MODULE LIST WOULD HAVE BEEN WRONG IN BOTH DIRECTIONS. It named
watchdog.py, which reduces over no roster at all (SAFETY-30's sign watchdogs are
strictly per-unit), and omitted maintenance.py and store.py, which both do. A vacuous
claim about one module and no claim at all about two others - which is the argument for
computing the scope, made with data.

The pin rediscovers ALL FOUR blockers without being told where to look, and finds a
FIFTH beside them (validate.py:783, rule 5's own message) that no review round named.
Its counterfactual runs at two depths: every enumerated site's expression mutated with
each of the four cuts this card has been defeated by (183 x 4 = 732 spellings, all
reported), and `[:1]` written into app/validate.py at each blocker position with the
WHOLE analysis re-run over the mutated source.

THE SWEEP, AND THE NUMBER THAT MUST NOT BE QUOTED ALONE

All 183 sites mutated to `[:1]`, +4 B each, against the full 19-file suite in
goodwe-addon-ci (:ro, -B, fresh rsync per mutant, 0 .pyc before and after - a read-only
mount cannot write one): 183/183 RED. ⚠️ That is TAUTOLOGICAL on its own, because the
pin makes every slice red. So the 51 whose first red was test_peakguard.py were re-run
with the pin NEUTRALISED:

  145 of 183   a behavioural fixture separates the site from a slice of itself
   38 of 183   ONLY the structural claim. Behaviourally UNGRADED.

All 38 are listed by site with what a `[:1]` there would cost, in the DECISIONS record
and in part 12j itself: 15 are rows and counts on the operator's page, 3 are
`len(targets)` arithmetic beside a write path that IS graded, 6 are allocator internals
ALLOC-01 reaches but not with enough units to separate. NONE of the 38 is closed
behaviourally by this card and none is counted as covered.

THE BEHAVIOURAL HALF, because a shape pin grades an identity and never a meaning

test_validate.py grows a ROSTER SET for the three rules that reduce over
`unit_caps_indexed()`: widths 2, 3, 4, 5 with the one small cap at EVERY position,
14 rosters x 3 rules = 42 runs of the real validator, each asserting the refusal fires
AND names the unit the number came off. Beside it a COMPUTED family table of twelve
candidates - max, first, last, the mean, [:1], [-1:], [:2], [:3], [1:], [:-1], [::2] -
each compared against what the shipped validator actually answered on the same roster.
Only `min` agrees everywhere; a member no roster kills is printed as a NAMED SURVIVOR.

⚠️ A THIRD RULE WAS READING THE FLAT `max_w`, AND IT IS SAFETY-30's

Found by reading the three branches side by side, NOT by the pin - and said that way
because it is the shape of what the pin cannot see. `unit_sign_disagree_w` was graded
against `_number(opts, "max_w", 2000.0)`, three lines under a branch that had already
stopped doing that. Both directions were measured before the fix:

  two 2000 W units + a leftover `max_w: 5000` + unit_sign_disagree_w 3000 -> 0 problems.
  The site started, the status page said `armed`, and the per-inverter watchdog could
  not trip on EITHER unit. Identical sentence to the blocker, one branch over.
  two 5000 W units with NO flat key -> REFUSED against a 2000 W default the operator
  never wrote, for a threshold both units can reach.

It takes the same `weakest` the branch above takes and names the same unit. At a roster
of one `unit_caps()` is `[max_w]`, so the shipped single-inverter refusal is the same
comparison, the same boundary and the same sentence.

MUTATION PROOF (each: bytecode purged and counted 0 before and 0 after, the edit
re-read FROM DISK with the new text present and the old absent, byte delta printed)

  B1  validate min(caps)     -> min(caps[:1])        +4 B  RED test_validate.py
  B2  validate min(caps)     -> min(caps[-1:])       +5 B  RED test_validate.py
  B3  validate caps_ix       -> caps_ix[:1]          +4 B  RED test_validate.py
  B4  validate rule 6 min    -> min(caps_ix[-1:])    +5 B  RED test_validate.py
  B5  validate rule 5 msg    -> min(caps_ix[:1])     +4 B  RED test_validate.py
  B6  validate rule 5b msg   -> min(caps_ix[-1:])    +5 B  RED test_validate.py
  B7  CONTROL: weakest -> max(0.0, weakest)         +10 B  GREEN, as intended
  R3a peakguard max(floors)  -> min(floors)           0 B  RED test_peakguard.py
  R3b peakguard max(floors)  -> max(floors[-2:])     +5 B  RED test_peakguard.py
  R3c main call site packs   -> self.packs[:2]       +4 B  RED test_peakguard.py
  R4a main pack_floor_soc    -> vals[:2]             +4 B  RED test_peakguard.py
  R4b main pack_floor_soc    -> vals[-2:]            +5 B  RED test_peakguard.py
  R4c main pack_floor_soc    -> vals[:3]             +4 B  RED test_peakguard.py
  R4d main cycle() any(...)  -> self.inverters[:1]   +4 B  RED test_watchdog.py

B1-B6 are caught by the BEHAVIOURAL set in test_validate.py, before the pin is reached.
B7 is a deliberate no-op control: `max(0.0, weakest)` is `weakest` for weakest > 0, and
it stays green, so the battery is not merely red for everything.

R3a is a ZERO-byte delta, so the shipped function was called both ways as well:
  packs floors [15.0, 30.0, 20.0], peak_soc_floor 15
  binding_soc_floor(...) = 30.0   the 0-byte mutant would answer 15.0   (+15.0 pp)
  -> the site would discharge to 15 % while pack-b's own BMS cuts out at 30 %.

⚠️ PRODUCTION IS DEGENERATE ON THE FLOOR AXIS. SPIKE-04: pack A and pack B BOTH floor
at 10 %, so a differing floor exists ONLY in the fixtures. That is the argument for
keeping them, not for simplifying them - collapsing them deletes the only data in this
repository that can see the reduction at all. Restated in config.yaml's example, in the
probe and in the fixtures.

⚠️ INVERTER B DOES NOT PHYSICALLY EXIST (~2026-09-12). Every second-unit figure here -
4600 W FROM ITS DATASHEET, 15 % illustrative, the whole roster SET - is SIMULATED and
labelled. Only inverter A's 10 % is read off hardware.

REBASED onto 67e649a. Two conflicts with SPIKE-04a, both in the blocks this card had
rewritten (config.yaml's roster example and the probe's C/D sections). Resolved to carry
BOTH claims, and the probe was RE-RUN rather than hand-merged: `all cases passed` on
ghcr.io/home-assistant/amd64-hassio-supervisor:2026.08.0, transcript updated with the
date. MUTATION.md habit 8 - a committed transcript stitched together out of two runs is
not a measurement.

Suite: 19/19 green in goodwe-addon-ci, mounted :ro, bytecode purged and verified 0
before and after. CI-06: test_peakguard.py run four times in isolation, green each time
(288 ok lines); test_validate.py three times, green each time.

MUTATION.md gains habits 12 and 13: build the instrument once the same shape has been
found twice AND make it discover its own scope, and say what the instrument cannot see
with sizes in the same breath.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU

goodwe_controller/CHANGELOG.md

@@ -2,6 +2,67 @@
 
 ## Unreleased
 
+**Inverter B's rating is 4600 W, FROM ITS DATASHEET, and every documented copy
+of it now says so (SPIKE-04a).** Three places stated B's rating — `config.yaml`'s
+commented roster example, `DOCS.md`'s, and `tools/supervisor_shape_probe.py`'s
+"a blob an operator would POST" — and all three said **3000 W**, a number that
+was never measured, never read off a datasheet, and simply wrong. The owner
+supplied B's model and serial on 2026-09-04: a **GoodWe GW5048D-ES**, serial
+`55048ESU22AW0992`, max charging and discharging power **4600 W**. No control
+behaviour changes here; this is documentation and its pin.
+
+* **Serial characters 6-8 read `ESU`** → platform 105, AA55, the supported set.
+  Not `ESN`/`ESC` (ES G2, platform 745). SPIKE-01 does not gate this site.
+  ⚠️ A passed platform gate is **not** a proven control surface: `specs.md`
+  already calls other platform-105 serials *"same protocol family; untested
+  silicon"*, and this repo's `0x056E`/`0x056F` map was reverse-engineered from a
+  passive tap on **one BPS unit**. That check is the bench half of SPIKE-04.
+* **⚠️ 4600 W IS FROM A DATASHEET AND IS NOT A MEASUREMENT, and one ambiguity is
+  recorded rather than guessed.** The datasheet prints it under *Battery Input
+  Data*, so it is probably **DC**, while `max_w` is graded against `0x0518` —
+  the inverter's own **AC** power. If it is DC the AC ceiling is nearer
+  4600 × 0.94 ≈ **4324 W**, and the charge direction moves the other way
+  (≈ 4894 W drawn AC-side). **Neither reading is written in as fact.**
+  SAFETY-20's `min(max_w, dev_max)` already bounds it correctly under either,
+  once `dev_max` is read off the unit — so `max_w: 4600` is what to configure
+  today. `goodwe/NOTES.md` §1.1b carries the full record, with the date and the
+  method on every figure.
+* **A NEW CHECK, BECAUSE A DOCUMENTATION FIX WITHOUT ONE DRIFTS AGAIN.**
+  `test_validate.py` now pins all three documented rosters: they must be
+  findable, they must agree, and they must say **4600**. It also grades the
+  **provenance beside the number** — the datasheet it came from, the `0x0518`
+  it is graded against, and the 4324 W the DC reading would make it — **within
+  2500 characters of the roster, not file-wide.** The first version searched
+  whole files and was already vacuous on two of them, because `0x0518` appeared
+  in `config.yaml` and `DOCS.md` for unrelated reasons before this card: a
+  check whose data could not reach the failure it named, in the file that
+  exists to complain about those. Four mutations were run against the fixed
+  version — the probe back to 3000 (0-byte delta), the `DOCS.md` caveat
+  deleted, `config.yaml` alone "corrected" to 4324 (0-byte delta), and the
+  probe's entity renamed so the regex finds nothing — and all four are red.
+* **THE TEST FIXTURES KEEP 3000 W ON PURPOSE, AND NOW SAY WHY AT THE LINE.**
+  `test_inverter.py`, `test_maintenance.py`, `test_peakguard.py` and
+  `test_watchdog.py` build a second inverter at 3000 W against A's 5000 W. The
+  only property those checks consume is that B's number is **unmistakably** not
+  A's, and the real pair is a **400 W** gap — narrower than `slew_w`, inside the
+  range where an off-by-one-unit bug and ordinary control arithmetic produce
+  indistinguishable numbers. Collapsing them onto the real values would buy
+  realism those checks do not use and cost them their separating power, which
+  is the defect `test_peakguard.py`'s own §10g precondition exists to prevent.
+  They are **illustrative, not B's rating, and no longer a placeholder for it**.
+* **Two consequences with numbers, recorded in `goodwe/NOTES.md` §1.1b for the
+  cards that own them.** At 94 % battery-to-AC a round trip is ≈ 88 %, so A
+  charging 3 kW while B discharges 3 kW burns ≈ **360 W continuously** with the
+  meter at zero — SAFETY-31 argues its threshold from *"a few watts"* and has no
+  figure. And **< 13 W night self-consumption per unit** (≈ 26 W for two,
+  ≈ 0.6 kWh/day), which nothing in this add-on accounts for anywhere.
+* **The site is asymmetric in opposite directions:** A = 5000 W / 15.36 kWh
+  nominal, B = 4600 W / 20.48 kWh — ~33 % more energy, ~8 % less power. No
+  stability implication (ARCH-01's ḡ = Σαᵢgᵢ is a convex combination), but a
+  full recalibration of B moves 33 % more energy and **MAINT-05's 12 h `drain`
+  phase timeout was derived on A**; it should be re-checked against B rather
+  than assumed to carry.
+
 **Every pack is recalibrated on its own schedule, and only one moves power at a
 time (MAINT-05).** §12's monthly cycle drains a pack to empty and refills it to
 true its coulomb counter. There was exactly one `Maintenance` state machine and
@@ -118,6 +179,284 @@ two power-moving phases on one grid connection pulling against each other.
   is loop and allocator territory. Pinned as a running check
   (`test_maintenance.py` part 12) so it cannot be forgotten.
 
+**`bms_soc_floor` describes a BATTERY, so at two packs it stops being one number
+(SAFETY-32).** The peak guard's energy backstop rests on two figures: the EMS
+floor `peak_soc_floor` (the depth a money-saving discharge may never reach) and
+`bms_soc_floor`, the percent **that pack's own BMS** cuts out at — register
+`0x0560`, read as 10 on the reference GW5000S-BP. Rule 8 refuses an EMS floor at
+or below the cut-out, because such a floor can never bind: the BMS wins and the
+status page reports a backstop that does not exist. With ONE cut-out for two
+packs of different models that rule graded the EMS floor against whichever
+battery happened to be written into the flat key, and a site with cut-outs of
+10 % and 30 % under `peak_soc_floor: 20` **started** — the guard would then
+command a forced discharge that pack B's BMS, not the operator's floor, is the
+thing that stops. Rule 8's own failure mode, reached through rule 8.
+
+* **`bms_soc_floor` becomes a per-entry roster key, and it is REQUIRED there.**
+  Nothing is inherited: an entry that omits it has no cut-out, does not borrow
+  the flat one, and is refused by name at startup. A per-entry *default* was
+  considered and declined — a default is one number for every pack, which is the
+  defect this card removes; `DECISIONS/SAFETY-32-per-pack-bms-floor.md` records
+  the decision and its migration cost. The flat key is unchanged and is now
+  documented as the single-inverter shape's own cut-out.
+* **Rule 8 grades EVERY unit and NAMES the one it refuses**, through a new
+  `unit_bms_floors_indexed()` that carries the **roster** index the value came
+  off. CFG-04 had just fixed a rule 5/6 bug of exactly this shape — a caps-list
+  index fed to a function that indexes the roster, so the message named the wrong
+  inverter — and this reader skips nothing, so there is no second list for an
+  index to desynchronise from. Graded on a roster whose offender is the SECOND
+  entry *and* on the same two numbers in the other order.
+* **The permission is answered PER PACK.** `Controller.pack_floor_soc` — the
+  emptiest measured pack — is untouched and is still what `decide()` grades;
+  what changed is the floor. `peakguard.pack_permissions()` answers one
+  `(name, reason)` per pack against that pack's own floor, and the floor-limited
+  notification now names the pack that stopped the site rather than "the
+  battery". At a roster of one the alarm is byte-for-byte what SAFETY-25 shipped.
+* **An unstated cut-out withholds rather than defaults.** `None`, not `0.0` —
+  `discharge_permitted()` already treats an unknown floor as no permission, so
+  the absence costs a shave and never a pack, including on `sim/inject.py`'s path
+  which does not run the startup gate.
+* ⚠️ **Stated rather than hidden:** under any config rule 8 accepts, the per-pack
+  *floor* reduces to `peak_soc_floor` for every pack — rule 8 makes it so. The
+  reduction is written for `unit_caps_indexed()`'s reason ("unreachable" is a
+  claim about rule ordering, not a property of a function) and is graded on both
+  sides: 1775 rule-8-valid `(peak_soc_floor, bms_soc_floor)` pairs answer the
+  option, and the pair rule 8 refuses answers the cut-out. `peak_soc_floor`
+  itself is still one number for the site, so the "deeper pack needlessly
+  withheld" half is filed as an open question, not closed.
+* **`tools/supervisor_shape_probe.py` re-run and repaired.** MUTATION.md habit 8:
+  a committed transcript is a check and it decays. The required key broke §C and
+  left §D printing PASS on a refusal about a *different* key. §D is now an
+  isolated counterfactual over an accepted, merged baseline, one key varied per
+  case, asserting the key **name** in the refusal — `all cases passed` on
+  `amd64-hassio-supervisor:2026.08.0`.
+* ⚠️ **SECOND FIX ROUND — the round-2 fix carried the defect it was written to
+  close, in its prose.** Two more rewrites survived a green 19-file suite on
+  `8501e05`: `binding_soc_floor()`'s `max(floors)` → `max(floors[-2:])` (+5
+  bytes) and the call site's `self.packs` → `self.packs[:2]` (+4 bytes). Both are
+  checks whose TEXT claimed more than their FIXTURE could reach — 12c2's only
+  counterfactual varied the **last** pack, which every window ending at the
+  roster's end follows, and all three 12g runs drove a **two**-pack roster, where
+  `[:2]` *is* the roster. **The general law, now stated in the file: a fixture of
+  N packs cannot separate two reductions that agree on N packs**, and the regress
+  does not terminate in a fixture — `[:1]` needed two packs, `[:2]` three, `[:3]`
+  four. So the reduction is now graded by a **length sweep** (78 simulated
+  rosters, lengths 1–12, deepest cut-out at every position, closing head and tail
+  windows of width 1–11 at once) plus a **computed family table** of fourteen
+  rewrites that goes red naming any member no roster kills; the call site is
+  graded by **three-pack runs** with the deep cut-out at index 0, 1 and 2, plus
+  an **exact structural pin** (the roster argument must unparse to `self.packs`)
+  for the slice widths no bounded roster can reach. Round 3's own battery found
+  `self.packs[:3]` / `[-3:]` surviving all six behavioural runs — the structural
+  pin is what closes them — and one row is recorded **NOT CAUGHT**: a reduction
+  over a window twelve packs wide, which needs a 13-pack roster to observe.
+  No shipped behaviour changed in this round; only what observes it.
+* **Twelve source mutations, eleven red, one argued survivor**, through
+  `tools/mutation_run.sh` (bytecode purged). The battery also found a real
+  weakness of its own: `_flat_bms_floor()` had the default in two places and each
+  covered for the other, so deleting either survived — masking, in three lines of
+  option reading. One defaulting line now.
+* ⚠️ **FIX ROUND — that battery was INCOMPLETE, and the review found what it
+  missed.** Neither of the two mutations below appears in the twelve rows above:
+  the ledger graded "the reduction dropped" and "the bare option handed over"
+  and never asked what happens when the reduction is simply the *wrong* one, or
+  when the roster handed to it is *sliced*. No shipped behaviour changed here;
+  two *checks* whose data could not reach the failure they named did. `max(floors)` → `min(floors)` in
+  `binding_soc_floor()` (zero byte delta) and `self.packs` → `self.packs[:1]` at
+  the `decide()` call site (+4 bytes) were each green across all 19 files. Both
+  survived for the same reason: **under any rule-8-valid config every pack's
+  `pack_floor_pct()` equals `peak_soc_floor`**, so `floors` is a list of
+  identical numbers and `max`, `min`, first and last are four spellings of one
+  answer — and the one check using a cut-out above the EMS floor ran on a roster
+  of ONE, where every reduction agrees. The second also walked through part 12g,
+  which asserted `"self.packs" in <the unparsed call site>`: a slice still
+  contains that substring, so the pin passed on the mutation that grades the
+  whole site against pack A. MUTATION.md habit 4 — a source-text test is a check
+  on how code is spelled, not on what it does.
+  * **New part 12c2** evaluates `binding_soc_floor()` on a roster whose per-pack
+    floors **all differ** — four simulated cut-outs of 30/25/40/35 %, every one
+    above `peak_soc_floor`, chosen so that `max` (40), `min` (25), first (30),
+    last (35) and the mean (32.5) are five different numbers and the two extremes
+    sit at *interior* roster positions. Two packs cannot separate those four;
+    four is the smallest roster that can. The precondition is its own check
+    (habit 1) and one pack — the last, neither deepest nor shallowest — is then
+    raised past the old maximum and the answer follows it (habit 7).
+  * **Part 12g is now behaviour, not source text.** Real `Controller.cycle()`s on
+    a two-pack roster, both packs at the same SoC, with the cut-outs as the only
+    thing varied: move the **non-first** pack's cut-out and the floor reaching
+    `decide()` moves 20 % → 35 %, with the site's verdict flipping from a sized
+    discharge to FLOOR-LIMITED. `self.packs[:1]` answers 20 % both times. Which
+    option key the floor comes from stays pinned on the source where it already
+    was, because that claim genuinely is about the code's shape.
+  * ⚠️ **Two MORE survivors, found by this round's own battery and recorded
+    rather than quietly repaired.** (a) The first cut of part 12g varied only
+    pack B's cut-out, so `self.packs[-1:]` — grade the site against the **last**
+    pack — agreed with the full roster on both runs and stayed green across all
+    19 files (+5 bytes). A two-run fixture pins one slice and not the other.
+    Part 12g now runs the **same pair of cut-outs in both orders**, so the
+    deeper one is on the second pack in one run and on the first in another and
+    the site floor is 35 % in both; no single-position slice passes all three
+    runs. (b) `binding_soc_floor()`'s empty-roster branch rewritten to
+    `return None` (−43 bytes) was also green — a defensive branch nothing in the
+    suite reached. Both directions of it are pinned now, with the note that it
+    cannot permit anything either way because `pack_floor_soc` is `None` at an
+    empty roster.
+
+* ⚠️ **THIRD FIX ROUND — the same family was alive at the SIBLING ARGUMENT of
+  the same call.** Rounds 2 and 3 hardened the FLOOR axis; `decide()` is handed
+  a second reduction over the same roster beside it, `soc=self.pack_floor_soc`,
+  and `peakguard.py`'s own docstring names the two as a pair. Three rewrites of
+  `Controller.pack_floor_soc` were green across all 19 files on `52380c0` and
+  again after the rebase onto `3934ad7`: `min(float(v) for v in vals)` →
+  `vals[:2]` (+4), `vals[-2:]` (+5) and `vals[:3]` (+4), while `[:1]`, `[-1:]`,
+  `[1:]`, `[:-1]`, `max()` and the mean were all red. **The suite's separating
+  power on the SoC axis stopped at exactly N=2** — the state the floor axis was
+  in before round 3. It changes a real answer: a three-pack roster at
+  50 / 60 / 11 % with the emptiest pack THIRD answers 11 % shipped and 50 %
+  mutated, so the site is graded for discharge PERMISSION against a pack 39
+  points fuller than the emptiest and spends a pack its own BMS stops. Round 3's
+  machinery transfers directly — new **part 12i**: six real `cycle()`s with the
+  emptiest pack at every position of a three-pack roster and both positions of a
+  two-pack one (the observable read off `PeakDecision.soc`, cut-outs held flat
+  so the floor axis cannot be what moved the answers); computed slice and
+  non-slice tables that go red naming any member nothing kills; a **length
+  sweep** of 78 real rosters, lengths 1–12, closing head and tail windows of
+  width 1–11 and recording width 12 as honestly unreached; a **none-guard
+  sweep** over the same 78; and **three exact structural pins** — the `vals`
+  comprehension must iterate the bare `self.inverters`, and both `any()` and
+  `min()` must reduce the whole `vals` — which close every slice width at every
+  roster length. No shipped behaviour changed; only what observes it.
+* ⚠️ **SPIKE-04: production is DEGENERATE on the floor axis, so the
+  differing-floor fixtures are the entire exposure.** Pack B is 4 × Dyness
+  DL5.0C, DoD 90 → floor 10 % — **FROM THE DATASHEET AND THE SERIAL; inverter B
+  does not exist and nothing about it is measured.** Pack A is DoD 90 → 10 % as
+  well, and that one *is* measured. Both packs therefore floor at the same value
+  in the field, `max(10, 10)` is 10 whatever it reduces, and a differing floor
+  exists **only in the fixtures**. That is the argument for keeping them, not for
+  simplifying them: anyone who collapses `A_PACK_FLOOR != B_PACK_FLOOR_SIM` to
+  one number deletes the only data this repository has that can see the
+  reduction at all, and part 12c2's precondition check goes red if they do. The
+  **SoC** axis has no such degeneracy — two batteries at the same state of
+  charge is a coincidence, not a configuration — which is what makes
+  `pack_floor_soc` the half of the pair that will be live from the day inverter
+  B is wired up.
+* ⚠️ **The FAMILY enumerated rather than the member closed, and it found four
+  more survivors in code this card never touched.** Every reduction over
+  `self.inverters` / `self.packs` in `Controller` was found from the AST and
+  mutated to a slice against the full suite. Eighteen were already graded
+  (`site_batt_w`, `site_rating_w`, `site_max_w`, `site_dev_bound`,
+  `site_circulating_w`, `inputs_ok`, `units`, `Controller.packs`, `maint_unit`,
+  the maintenance-due minimum, the store-migration roster, `validate_unit_ranges`
+  and the round-2/3 sites). **Four were not, and three of them are SAFETY-30's,
+  all `any(i.sign_wd.tripped for i in self.inverters)`** — `cycle()`'s
+  stale-input hold, `publish()`'s status vocabulary and `status_payload()`'s
+  banner — each +4 bytes and green across all 19 files, for the reason every
+  blocker on this card was invisible: **the only fixture that reached them was a
+  roster of ONE, where `self.inverters[:1]` IS `self.inverters`.** The first has
+  teeth: a latched unit must take the roster past that hold or its `failsafe`
+  SET stops being re-filed the moment a poll is missed, which is main.py's own
+  sentence for it. New **test_watchdog.py part 8** grades all three with the
+  latch at EACH position plus a no-latch counterfactual, and new **part 12j**
+  pins all 26 roster comprehensions in `Controller` to iterating the roster
+  whole — so a reduction added over a slice anywhere in the class is red on the
+  line it is written, with no fixture required. Two rows are reported open
+  rather than closed: `_grade_store_migration()`'s second disjunct (now red on
+  12j, and argued to be an equivalent mutant because a unit tripped at startup
+  implies its namespaced key is set) and `cycle()`'s undeliverable-unit **log
+  line**, where `sorted(...)[:1]` (+4 bytes) is still green — it truncates names
+  in one event message; the refusal itself is a different expression and is
+  graded, so the site still stops.
+* ⚠️ **FOURTH FIX ROUND — the same family one MODULE over, and the pin widened
+  until it discovers its own scope.** Round 4 enumerated the family and closed
+  it inside the `Controller` class; the review found four more survivors
+  immediately, in **validate.py**, on a 19/19 green suite: `min(caps)` →
+  `min(caps[:1])` (+4) and `→ min(caps[-1:])` (+5) at `:779`, the caps
+  comprehension over `caps_ix[:1]` (+4) at `:778`, and
+  `min(caps_ix[-1:], key=…)` (+5) at `:893`. **None is an equivalent mutant.**
+  With `max_w: 5000` on inverter-a beside `2000` on inverter-b and
+  `sign_disagree_w: 3000`, the shipped validator refuses — *"the SAFETY-02
+  sign-disagreement watchdog can never fire"* — and all four **accept**: the
+  site starts with a watchdog reporting `armed` that cannot trip on pack B.
+  Rule 5's own failure mode reached through rule 5; rule 6 loses its refusal the
+  same way. **No shipped behaviour changed by the pin; what changed is that a
+  hand-written scope stopped being trusted.**
+  * **`test_peakguard.py` part 12j now parses every `.py` under `app/`** — no
+    module is named in the check — and finds the roster by transitive closure
+    from **one seed**, the `inverters` option key: through returns, through
+    lists **accumulated in a loop over a roster** (which is what `caps`,
+    `roster` and `problems` are, and what round 4's rule could not express),
+    through attributes and properties, and **through call arguments**, which is
+    how it walks into `peakguard`, `arbiter`, `allocator`, `circulation`,
+    `maintenance` and `store` without being told they exist. A slice of a roster
+    stays a roster so a mutation cannot cut the taint; an index is one unit and
+    does not. **183 reductions across 9 modules** out of 23 files parsed — `main.py` 96,
+    `allocator.py` 24, `validate.py` 19, `arbiter.py` 14, `circulation.py` 10,
+    `maintenance.py` 10, `peakguard.py` 4, `inverter.py` 3, `store.py` 3.
+  * **The hand-written module list would have been wrong in BOTH directions.**
+    It named `watchdog.py`, which reduces over no roster at all — SAFETY-30's
+    sign watchdogs are strictly per-unit — and omitted `maintenance.py` and
+    `store.py`, which both do. A vacuous claim about one module and no claim
+    about two others.
+  * **The pin rediscovers all four blockers without being told where to look,**
+    and finds a fifth beside them (`validate.py:783`, rule 5's message) that no
+    review round named. Its counterfactual runs at two depths: every enumerated
+    site's own expression mutated with each of the four cuts this card has been
+    defeated by (732 spellings, all reported), and `[:1]` written into
+    `app/validate.py` at each blocker position with the **whole** analysis
+    re-run over the mutated source — a sliced site required at that exact line,
+    where the clean package reports none.
+  * **And the behavioural half, because a shape pin grades an identity and never
+    a meaning.** `test_validate.py` grows a **roster SET** for the three rules
+    that reduce over `unit_caps_indexed()` — widths 2, 3, 4, 5 with the one
+    small cap at every position, 42 runs of the real validator — plus a
+    **computed family table** of twelve candidate reductions each compared with
+    what the shipped validator actually said on the same roster. Only `min`
+    agrees everywhere; a member no roster kills is printed as a named survivor.
+  * ⚠️ **A THIRD RULE WAS READING THE FLAT `max_w`, AND IT IS SAFETY-30's** —
+    found by reading, **not** by the pin, which is the shape of what the pin
+    cannot see. `unit_sign_disagree_w` was graded against
+    `_number(opts, "max_w", 2000.0)` three lines under a branch that had already
+    stopped doing that. **Both directions were measured:** two 2000 W units
+    beside a leftover `max_w: 5000` and `unit_sign_disagree_w: 3000` produced
+    **zero problems** — the site started with a per-unit watchdog that could not
+    trip on either unit — and two 5000 W units with no flat key were **refused**
+    against a 2000 W default the operator never wrote. It takes the weakest
+    unit's own cap now and names that unit; at a roster of one it is the same
+    comparison, boundary and sentence it always was.
+  * ⚠️ **What the pin cannot see, with sizes**, in
+    `DECISIONS/SAFETY-32-per-pack-bms-floor.md` §4d: semantics (`min` vs `max`
+    is a zero-byte edit); direct index sites that are not reductions; a
+    subscript by a *variable* (`weights[u]` is why); a slice through an
+    intermediate call; anything outside `app/`, including `sim/inject.py`; and
+    the taint's own seam at `*args` and unresolvable receivers, where everything
+    downstream goes **unenumerated rather than reported unreachable**.
+    `cycle()`'s undeliverable-unit log line is still green at +4 bytes and still
+    filed open, unchanged from round 4.
+  * **`tools/supervisor_shape_probe.py` re-run again (2026-09-05, 2026.08.0).**
+    The rebase onto `67e649a` merged SPIKE-04a's `max_w: 4600` into the same
+    §C/§D blocks this card had rewritten, and a transcript stitched by hand out
+    of two runs is not a measurement. `all cases passed`, exit 0, with B's
+    rating reading 4600 — its **datasheet** figure, still not a measurement of
+    any unit.
+  * ⚠️ **THE SWEEP, AND THE NUMBER THAT MUST NOT BE QUOTED ALONE.** All 183
+    sites mutated to `[:1]`, one at a time, against the full 19-file suite in
+    `goodwe-addon-ci` (`:ro`, `-B`, fresh rsync per mutant, 0 `.pyc` before and
+    after): **183/183 RED** — which is tautological on its own, because the pin
+    makes every slice red. The 51 whose first red was `test_peakguard.py` were
+    re-run with the pin **neutralised**: **145 of 183 have a behavioural fixture
+    that separates them from a slice of themselves; 38 have only the structural
+    claim.** All 38 are listed by site, with what a `[:1]` there would cost, in
+    §4d and in `test_peakguard.py` part 12j — 15 of them are rows and counts on
+    the operator's page, 3 are `len(targets)` arithmetic beside a write path
+    that IS graded, 6 are allocator internals ALLOC-01's fixtures reach but not
+    with enough units to separate. **None of the 38 is closed behaviourally by
+    this card, and none is counted as covered.**
+
+⚠️ **No measurement of inverter B appears anywhere in this change.** It does not
+exist yet. Every second-pack figure — in fixtures, in the probe, in
+config.yaml's commented example — is **simulated and labelled**; only inverter
+A's 10 % is read off hardware.
+
 **At two inverters the sign watchdog stops comparing one unit against the whole
 site meter, and becomes two checks instead of one (SAFETY-30).**
 `disagrees(commanded_w, grid_w, ...)` compared the command **this controller put

goodwe_controller/DECISIONS/SAFETY-32-per-pack-bms-floor.md

@@ -0,0 +1,816 @@
+# SAFETY-32 — `bms_soc_floor` per pack, and the two judgement calls it left open
+
+**Status:** decided and implemented on branch `SAFETY-32`.
+**Card:** SAFETY-32 — *"One `bms_soc_floor` for two packs grades the shallower
+pack against the deeper one's cut-out"*, scoped by the card's own PM PROOFREAD
+to its **third** bullet only. Bullets 1 (aggregate anti-windup) and 2 (per-instance
+`achievable_w`) were verified as already shipped by DEV-02 and CFG-04 and were
+**not** touched — `main.py`'s `actual_w=self.site_batt_w` comment is the record
+of why the first of those must stay site-level, and it still reads as written.
+
+---
+
+## 1. The defect, stated in the terms the code uses
+
+`bms_soc_floor` **describes a battery**: it is the percent that pack's own BMS
+cuts out at, register `0x0560` on the reference GW5000S-BP, read as 10. It was a
+flat option because there was one pack.
+
+`peak_soc_floor` **describes the site's policy**: the depth a money-saving
+discharge may never reach. Rule 8 refuses `peak_soc_floor <= bms_soc_floor`,
+because such a floor can never bind — the BMS wins and the status page reports a
+backstop that does not exist.
+
+At two packs of different models the two cut-outs differ, and one number for both
+is wrong **in the direction that empties a pack**: with cut-outs of 10 % and 30 %
+and `peak_soc_floor: 20`, the add-on **started**, and the guard would command a
+forced discharge that pack B's *BMS* — not the operator's floor — is the thing
+that stops. That is rule 8's own failure mode, reached through rule 8.
+
+---
+
+## 2. DECISION 1 — required per entry, not defaulted from `PEAK_OPTION_DEFAULTS`
+
+The card left this open and asked for the reason to be recorded.
+
+**Decided: REQUIRED of every roster entry**, in `config.yaml`'s schema
+(`bms_soc_floor: int(0,50)`, no trailing `?`) and in `validate.py` rule 8, which
+refuses a missing one **by name**.
+
+The reason is that a default here is not a convenience, it is **this card's own
+defect wearing a different hat**. A default is one number applied to every pack,
+which is exactly what the flat key was. An add-on that answers "10 %" for a pack
+nobody has told it about has invented a property of somebody's battery, and the
+failure mode of the invention is the one this card exists to remove — the
+shallower pack protected by a floor that belongs to the deeper one. CFG-03's
+rule ("defaults live in exactly one place") points the same way: the one mirror
+`PEAK_OPTION_DEFAULTS["bms_soc_floor"]` is the default for the **flat** key, i.e.
+for the single-inverter shape, and reusing it per entry would make one dict the
+default in two shapes with two meanings.
+
+It is also the treatment `max_w` already gets, for the same reason and by the
+same argument (`inverter.py`'s `build_roster()` docstring): the per-unit numbers
+that describe hardware are required, and the per-unit *sensors* are optional
+because an absent sensor is a real state.
+
+**The cost is stated rather than hidden.** This is a schema change: a roster
+config written before this branch is refused by the Supervisor until each entry
+gains the key, and every roster fixture in the suite needed it. Nothing in
+production carries a roster today — `inverters:` ships `[]` and the second
+inverter is ~8 days out — so the migration is paid by fixtures and by whoever
+writes the first real roster, at a startup refusal that names the entry.
+
+**What is NOT inherited.** An entry that omits the key does not borrow the flat
+one. `Inverter.bms_soc_floor` is then `None`, `peakguard.pack_floor_pct()`
+answers `None`, and `discharge_permitted()` already treats an unknown floor as
+**no permission** — so even in the window before rule 8 runs (e.g. `sim/inject.py`,
+which does not run the startup gate) the absence costs a shave and never a pack.
+`0.0` was rejected explicitly: it is the most permissive value the key has.
+
+## 3. DECISION 2 — the site verdict is the MAXIMUM of the packs' own floors
+
+`Controller.pack_floor_soc` — the **minimum** measured SoC, the emptiest pack —
+**is unchanged**, exactly as the card instructed. What changed is the floor it is
+graded against. `peakguard.binding_soc_floor()` reduces the roster's per-pack
+floors, each of them `max(peak_soc_floor, that pack's own cut-out)`, with a
+`max()`. The two reductions pair: a minimum SoC against a maximum floor is the
+conservative combination, and both move the verdict towards refusing a shave and
+away from spending a pack. `min(soc) <= max(floor)` is implied by "some pack is
+at or below its own floor", so the site verdict is never more permissive than
+grading each pack separately would be. The converse is not true and is not
+claimed — a site can be refused while every pack individually has headroom, which
+costs a shave.
+
+### 3a. ⚠️ FIX ROUND — the reduction was written and argued, and NOT GRADED
+
+PR #48 was rejected because the argument in §4 below justified *writing* the
+reduction and was then not carried into a check. Neither of the two mutations
+below appears anywhere in §6's twelve-row battery: it graded *"the reduction
+dropped"* and *"the bare option handed over"*, and never asked what happens when
+the reduction is the **wrong one**, or when the roster handed to it is
+**sliced**. Both were applied to `app/` by the reviewer and **all 19 files
+stayed green**:
+
+| mutation | Δ | why it survived |
+|---|---|---|
+| `binding_soc_floor()`: `max(floors)` → `min(floors)` | **0 bytes** | every roster in the suite was rule-8-valid or one pack long, so `floors` held **identical numbers** and `max`/`min`/first/last were four spellings of one answer |
+| the `decide()` call site: `self.packs` → `self.packs[:1]` | **+4 bytes** | part 12g asserted `"self.packs" in <the unparsed expression>` — and `self.packs[:1]` **contains that substring** |
+
+The zero-byte one was proved to have actually run rather than assumed:
+`dis.get_instructions` showed the `LOAD_GLOBAL`s as `[float, pack_floor_pct,
+any, min]`, and `binding_soc_floor([Pack("a",50,10), Pack("b",50,35)], 20.0)`
+returned `20.0` where the shipped code returns `35.0`.
+
+**The common cause is this repository's recurring defect** — a check whose DATA
+cannot reach the failure it names. The one check that used a cut-out **above**
+the EMS floor (12c's `_n1_deep`) ran on a roster of **ONE**, where every possible
+reduction agrees. So no check in the suite ever evaluated
+`binding_soc_floor()` on two packs whose floors **differ**.
+
+**And the rule-8 degeneracy is not a defence, by §4's own words.** If
+"unreachable is a claim about today's rule ordering, not a property of this
+function, and `validate_startup_config()` is also `sim/inject.py`'s entry point"
+is enough to *write* the reduction, it is enough to *grade* it. Through
+`sim/inject.py`, which does not run rule 8 at all, `min(floors)` lets the guard
+command a forced discharge to 20 % on a pack whose BMS cuts out at 35 %.
+
+**What was added — no shipped behaviour changed, only what observes it:**
+
+* **`test_peakguard.py` part 12c2** evaluates `binding_soc_floor()` on a roster
+  whose per-pack floors **all differ**. Four **simulated** cut-outs —
+  `30, 25, 40, 35` %, every one strictly above `peak_soc_floor: 20`, so
+  `pack_floor_pct()` selects the cut-out for each and `floors` *is* that tuple in
+  that order. The four candidate reductions are then four different numbers:
+
+      max   = 40   <- the shipped answer
+      min   = 25
+      first = 30   <- "grade the site against pack A", inside the function
+      last  = 35
+      mean  = 32.5
+
+  The extremes sit at **interior** roster positions (index 2 is the max, index 1
+  the min). A two-pack roster structurally cannot separate these — there `max`
+  and `last` coincide and so do `min` and `first` — and neither can three. Four
+  is the smallest roster that separates all four. The precondition is its own
+  check (habit 1), one pack is then raised past the old maximum (habit 7: the
+  **last** pack, which was neither extreme, so the line can only move if the
+  reduction read it), and `peak_soc_floor` is lifted above every cut-out to grade
+  the other side of the conjunction.
+
+* **Part 12g is behaviour now, not source text** (MUTATION.md habit 4). Real
+  `Controller.cycle()`s on a two-pack roster, both packs held at the same SoC and
+  everything else identical, with the packs' own cut-outs as the only thing
+  varied:
+
+      cut-outs A 10 / B 18 % -> decide() got soc_floor=20 %, floor_limited=False
+      cut-outs A 10 / B 35 % -> decide() got soc_floor=35 %, floor_limited=True
+
+  The observable is `PeakDecision.soc_floor` — the argument, echoed back by the
+  shipped `decide()` — so the whole path from `Controller.inverters` to the
+  guard's argument is under test, and the site's **verdict flips** as well as the
+  number. `self.packs[:1]` answers 20 % both times. **Which** option key the floor
+  comes from stays pinned on the source in part 4, because that claim genuinely
+  is about the code's shape; that the option still governs is now graded
+  behaviourally too.
+
+* ⚠️ **A THIRD SURVIVOR, FOUND WHILE FIXING THE FIRST TWO, AND RECORDED RATHER
+  THAN QUIETLY REPAIRED.** The first cut of part 12g varied only **pack B's**
+  cut-out — so `self.packs[-1:]`, grade the site against the **last** pack,
+  agreed with the full roster on both runs and stayed green across all 19 files
+  (+5 bytes). A two-run fixture that only ever moves the second pack pins `[:1]`
+  and not `[-1:]`; it is the same defect one step along, and it was in the fix
+  for this defect. Part 12g now runs the **same pair of cut-outs in both
+  orders**:
+
+      cut-outs A 10 / B 18 % -> soc_floor=20 %, floor_limited=False
+      cut-outs A 10 / B 35 % -> soc_floor=35 %, floor_limited=True
+      ...the SAME PAIR SWAPPED, A 35 / B 18 % -> soc_floor=35 %, floor_limited=True
+
+  `[:1]` answers 20 % on the second run, `[-1:]` answers 20 % on the third, and
+  the roster answers 35 % on both. No single-position slice passes all three.
+  This is the mirror `12h` already ran on the SoC axis, which is where the shape
+  was borrowed from.
+
+* ⚠️ **AND A FOURTH, from the same battery: the EMPTY-roster branch.** Rewriting
+  `binding_soc_floor([])`'s `float(soc_floor)` to `return None` (−43 bytes) was
+  green across all 19 files. It is defensive code — `Controller.inverters` is
+  never empty on a started controller, and `inputs_ok` refuses the cycle before
+  the guard is reached if it were — so nothing in the suite went near it. It is
+  **pinned rather than argued**, in both directions (the option when there is
+  one, `None` when there is not), because a branch with no check is a branch
+  that can be rewritten under a green suite. The check also records why it
+  cannot permit anything either way: `pack_floor_soc` is `None` at an empty
+  roster, and `discharge_permitted()` refuses on a `None` SoC whatever the floor
+  is.
+
+* **`wired_over_limit()` gained a `prepare(ctl)` hook**, inside its retry loop so
+  every attempt grades the same site, which is the only window in which a second
+  inverter can join the roster before the telegrams are fed.
+
+* **In-process mutation rows 22, 22b and 23** record all four survivors, so a
+  later edit that re-degenerates any of these fixtures goes red on a row rather
+  than on nothing.
+
+### 3b. ⚠️ SECOND FIX ROUND — the fix carried the defect it was written to close
+
+Round 2 closed both named survivors, and both of round 3's blockers are the
+**same defect sitting inside that fix**: a check whose TEXT claims more than its
+FIXTURE can observe. Applied to `app/` on `8501e05`, **all 19 files stayed
+green** for both:
+
+| mutation | Δ | the sentence that was too broad | why the fixture could not see it |
+|---|---|---|---|
+| `binding_soc_floor()`: `max(floors)` → `max(floors[-2:])` | **+5 bytes** | *"So the reduction reads **every entry**"* | 12c2's only counterfactual raised the **last** pack (`_deeper[-1]`), and **every window that ends at the roster's end follows the last pack**. On `(30,25,40,35)` both answer 40; on `_deeper` both answer 45. |
+| the `decide()` call site: `self.packs` → `self.packs[:2]` | **+4 bytes** | *"what is reduced is the **ROSTER** and not a POSITION in it"* | all three `_floor_reaching_decide` runs drove a **two-pack** roster, where `self.packs[:2]` **is** `self.packs` — by exactly the argument 12c2 itself makes about two packs being unable to separate max/min/first/last. |
+
+Round 2's *report* stated the narrow, true claim ("no **single-position** slice
+passes all three runs"). The *check in the file* stated the broad one. That gap
+is the whole of round 3.
+
+**THE GENERAL LAW, stated once so the next card can use it:**
+
+> **A fixture of N packs cannot separate two reductions that agree on N packs.**
+> Two cannot separate max from min from first from last. Three cannot separate
+> max from max-of-the-last-two. A single counterfactual that varies one position
+> cannot separate the reduction from any window containing that position.
+
+Its corollary is the reason this section is long: **the regress does not
+terminate in a fixture.** Closing `[:1]` took two packs; `[:2]` took three;
+`[:3]` takes four — and a four-pack run hands `[:4]` the same free pass. Round 3
+therefore does two different things rather than adding one more pack.
+
+**What was added — no shipped behaviour changed, only what observes it:**
+
+* **Part 12c2 gained a ROSTER SET and a computed FAMILY TABLE.** The same four
+  simulated cut-outs with the **deepest moved to each of the four positions**,
+  and fourteen enumerated rewrites of `max(floors)` each checked against every
+  roster. The table is **computed and printed**, and a member with an empty kill
+  list takes the check **red naming it** — so a family member can no longer be
+  added without a fixture that reaches it. `max(floors[-2:])` is killed only by
+  the rosters whose deepest sits at index 0 or 1, which is precisely the data the
+  single last-pack counterfactual could not supply.
+
+* **Part 12c2 gained a LENGTH SWEEP.** `binding_soc_floor()` is a pure function
+  over a list, which is the one place a sweep is cheap: **78 simulated rosters,
+  lengths 1 through 12, the deepest cut-out at every position of each.** That
+  closes *every* head window `max(floors[:w])` and *every* tail window
+  `max(floors[-w:])` of width **1 to 11** in one property rather than one
+  mutation at a time — and the check asserts that width **12 is NOT reached**, so
+  the limit is a red line rather than a silence.
+
+* **Part 12g drives THREE-pack rosters**, with the deep cut-out at index 0, 1
+  **and** 2. Every positional slice of a three-pack roster is a proper subset of
+  `{0,1,2}` and so drops a position; the run whose deep pack sits there answers
+  the option, 20 %, where the roster answers 35 %. `self.packs[:2]` goes red on
+  the index-2 run. `_floor_reaching_decide()` now takes `*floors`, and the extra
+  units join through the same `second_inverter()` hook the two-pack runs use.
+
+* **Part 12g gained a POSITIONAL-SLICE TABLE**, computed against the **real**
+  `Controller.packs` each of the six cycles actually ran and the **real**
+  `PeakDecision.soc_floor` it produced — so it measures the shipped call site's
+  own answer, not a re-derivation, and a survivor takes the check red.
+
+* ⚠️ **AND A FIFTH AND SIXTH SURVIVOR, FOUND BY ROUND 3'S OWN BATTERY AND
+  CLOSED STRUCTURALLY RATHER THAN BY ONE MORE PACK.** `self.packs[:3]` (+4) and
+  `self.packs[-3:]` (+5) survive **all six** behavioural runs, because the
+  longest roster those runs drive is three packs long. Part 12g therefore also
+  pins the roster **argument's identity** on the AST: it must unparse to exactly
+  `self.packs`, which is false of every slice at every length. ⚠️ This is **not**
+  the substring test round 2 removed — `"self.packs" in expr` is *true* of every
+  slice; `ast.unparse(arg) == "self.packs"` is *false* of all of them. The two
+  halves are separated and each says what it reaches: the **runs** grade the
+  VALUE and reach every slice up to N=3; the **pin** grades the ARGUMENT'S
+  IDENTITY at any N and is blind to two things the runs are not — a rewrite of
+  what `Controller.packs` *returns* (the runs' `len(ctl.packs) == 3` catches
+  that) and the reduction *inside* `binding_soc_floor()` (12c2's).
+
+* ⚠️ **AND ONE ROW IS RECORDED AS NOT CAUGHT.** A reduction over a window
+  **twelve packs wide** is indistinguishable from `max(floors)` on every roster
+  in the file, because the sweep stops at twelve. Unlike the call site there is
+  no identity claim to pin — the claim is semantic, "the maximum", and a shape
+  pin would refuse honest refactors of the expression. It is reported **with its
+  size** (it needs a 13-pack roster, on a site whose roster is ONE and whose
+  second unit is ~8 days out) rather than hidden.
+
+* **Two rewrites are EQUIVALENT, not uncaught.** `max(set(floors))` and
+  `list(reversed(self.packs))` cannot change any answer — `max` is order- and
+  duplicate-invariant. The second is nonetheless red on the structural pin.
+
+* **In-process mutation rows 24 – 27** record all four of round 3's findings,
+  including the not-caught one, so a later edit that re-degenerates any of these
+  fixtures goes red on a row rather than on nothing.
+
+## 4. ⚠️ THE HONEST LIMITATION, and it is the reason this record exists
+
+**Under any configuration rule 8 accepts, `binding_soc_floor()` answers
+`peak_soc_floor` for every pack.** Rule 8 refuses `peak_soc_floor <= bms_soc_floor`
+on *every* unit, so `max(peak_soc_floor, bms_i) == peak_soc_floor` everywhere the
+add-on will actually start. The per-pack **floor** is therefore non-degenerate
+only against a config rule 8 refuses.
+
+This is not a defect and it is not hidden. It is the same argument
+`validate.unit_caps_indexed()` makes about itself, in that function's own words:
+
+> *"Rule 9(d) already refuses such a config so the two lists cannot desynchronise
+> in shipped use — but 'unreachable' is a claim about today's rule ordering, not
+> a property of this function, and `validate_startup_config()` is also
+> `sim/inject.py`'s entry point."*
+
+CFG-04's index desynchronisation is what happened the last time that reasoning
+was left implicit. So the reduction is written, and it is graded on both sides:
+`test_peakguard.py` part 12c sweeps **1775** rule-8-valid `(peak_soc_floor,
+bms_soc_floor)` pairs and asserts the answer is the option in every one of them
+(that is AC 5, measured over the whole option space rather than at the shipped
+point), and then asserts that on the pair rule 8 *refuses* the answer is the
+**cut-out** — because without that second line the sweep would be satisfied by
+`soc_floor` typed straight through, and the mutation that deletes the `max()`
+could never bite. It does bite: M2 on the PR.
+
+**What IS live at a rule-8-valid roster** is the rest of the card: rule 8 now
+refuses the two-model config that used to start; the permission is answered per
+pack, so the alarm names the pack that stopped the site rather than "the
+battery"; and an entry with no stated cut-out is withheld instead of defaulted.
+
+## 4b. ⚠️ ROUND 4 — the sibling argument, and SPIKE-04 making this the live axis
+
+Rounds 2 and 3 hardened the **floor** axis: the `max` inside
+`binding_soc_floor()`, the roster handed to it, `Controller.packs`, and
+`pack_floor_pct()`'s conjunction. Round 4's blocker is the same family at the
+**sibling argument of the same call**:
+
+```python
+self.peak_guard = peakguard.decide(
+    ...,
+    soc=self.pack_floor_soc,                      # MINIMUM  <- round 4
+    soc_floor=peakguard.binding_soc_floor(self.packs, ...),   # MAXIMUM  <- rounds 2-3
+```
+
+`peakguard.py`'s own docstring names them as a pair — *"MAXIMUM here pairs with
+the MINIMUM in `pack_floor_soc`"* — and a conjunction is exactly as strong as
+its weaker half. On `52380c0`, with all 19 files green and verified again after
+the rebase onto `3934ad7`:
+
+| mutation in `Controller.pack_floor_soc` | bytes | before round 4 | now |
+|---|---|---|---|
+| `min(float(v) for v in vals[:2])`  | +4 | **GREEN** | RED |
+| `min(float(v) for v in vals[-2:])` | +5 | **GREEN** | RED |
+| `min(float(v) for v in vals[:3])`  | +4 | **GREEN** | RED |
+| `vals[:1]`, `vals[-1:]`, `vals[1:]`, `vals[:-1]`, `max(vals)`, the mean | | RED | RED |
+
+The suite's separating power on the SoC axis stopped at exactly **N = 2** —
+precisely the state the floor axis was in before round 3, and which round 3
+itself named as its blocker 2. A fixture of N packs cannot separate reductions
+that agree on N packs.
+
+**It changes a real answer.** A three-pack roster at 50 / 60 / 11 %, emptiest
+pack **third**: the shipped property answers 11 %, `vals[:2]` answers 50 %. The
+site is then graded for discharge *permission* against a pack 39 points fuller
+than the emptiest, and spends a pack its own BMS stops — through
+`sim/inject.py`, which runs no validator rule at all. The verdict flips with it:
+11 % is below the 20 % EMS floor, so the shipped site is floor-limited and sizes
+no forced discharge, where the mutant is permitted and sizes a positive one.
+
+### ⚠️ SPIKE-04 makes the differing-floor discipline the entire exposure
+
+SPIKE-04 reads pack B as **4 × Dyness DL5.0C, DoD 90 → floor 10 %** — **FROM THE
+DATASHEET AND THE SERIAL. Inverter B does not physically exist (~8 days out) and
+nothing about it has been measured.** Pack A is DoD 90 → 10 % as well, and *that
+one is measured*, off register `0x0560` on the reference GW5000S-BP.
+
+So **production is degenerate on the floor axis**: both packs floor at the same
+value, `max(10, 10) == 10`, and a differing floor exists **only in the
+fixtures**. That is not an argument for simplifying the fixtures to matching
+values — it is the argument for keeping them. `binding_soc_floor()`'s reduction
+is observable *nowhere else*, and the moment a third pack, a replacement pack or
+a different chemistry arrives it is observable in the field. **Anyone who
+"simplifies" `A_PACK_FLOOR != B_PACK_FLOOR_SIM` to one number deletes the only
+data this repository has that can see the reduction at all**; part 12c2's
+precondition check goes red if they do, and this paragraph is why.
+
+The **SoC axis has no such degeneracy**. Two batteries at the same state of
+charge is a coincidence, not a configuration, so `pack_floor_soc` is the half of
+the pair that will be non-degenerate in the field from the day inverter B is
+wired up.
+
+### The treatment, transferred from round 3
+
+* **the roster SET** — six real `Controller.cycle()` runs, the emptiest pack at
+  every position of a three-pack roster and both positions of a two-pack one,
+  the observable read off `PeakDecision.soc` (the argument, echoed) rather than
+  off a spy or a grep. Cut-outs held flat across all of them, so the floor axis
+  cannot be what moved the answers.
+* **the positional-slice table and the non-slice table** — computed against the
+  real `Controller.inverters` each cycle carried and the real decision it
+  produced, printed, with a member that nothing kills taking the check red.
+* **the length sweep** — the real property on real rosters of 1 to 12 inverters,
+  the empty pack at every position. Closes head and tail windows of width 1-11
+  at once. Width 12 and wider is **honestly not reached**, and asserted to be
+  unreached so a later sweep that lengthens the rosters must rewrite the
+  sentence.
+* **the exact structural pin** — three of them, because there are three
+  reductions over roster length in this one property: `vals` is built by one
+  comprehension over the bare `self.inverters`; `any(... for v in vals)` reduces
+  the whole list; `min(... for v in vals)` reduces the whole list. Every slice
+  of either is red at **every** roster length, including the `[:3]` and `[:12]`
+  the runs and the sweep cannot see.
+
+Unlike the floor axis, **there is no uncaught row here**: the claim at
+`pack_floor_soc` is an *identity* ("this list"), so a shape pin is the right
+instrument, where `binding_soc_floor()`'s claim is *semantic* ("the maximum")
+and a shape pin there would refuse honest refactors. That asymmetry is why one
+carries an open row and the other does not.
+
+## 4c. ⚠️ THE ENUMERATION — what OTHER reductions over roster length are graded
+
+This card has now been rejected three times for the same shape one step over, so
+round 4 stopped closing members and enumerated the **family**. Every reduction
+over `self.inverters` / `self.packs` in `Controller` was found from the AST and
+mutated to a slice, one at a time, against the full 19-file suite.
+
+| # | site | reduction | consumer | mutation | result |
+|---|---|---|---|---|---|
+| 1 | `pack_floor_soc` | `min` over SoC | `decide(soc=)`, `arbitrage.decide(soc=)` | `vals[:2]` +4 | **was GREEN → now RED** (12i) |
+| 2 | `pack_floor_soc` | `any(v is None)` | same | `vals[:1]` +4 | RED (raises in 12d; pinned in 12i) |
+| 3 | `pack_floor_soc` | the `vals` comprehension | same | `self.inverters[:2]` +4 | RED (12i sweep + pin) |
+| 4 | `binding_soc_floor` | `max` over floors | `decide(soc_floor=)` | `min`, windows | RED (12c2, round 2-3) |
+| 5 | call site | the roster argument | same | `self.packs[:1..3]` | RED (12g, round 3) |
+| 6 | `Controller.packs` | the comprehension | `binding_soc_floor`, `pack_permissions` | `self.inverters[:2]` +4 | RED (12g three-pack runs) |
+| 7 | `site_batt_w` | `sum` + `any(None)` | `decide(batt_w=)` — sizes the floor | `self.inverters[:1]` +4 | RED (test_inverter.py) |
+| 8 | `site_rating_w` | `sum` of per-unit conjunction | `decide(achievable_w=)`, freeze rail | `[:1]` +4 | RED (test_inverter.py) |
+| 9 | `site_max_w` | `sum` of `max_w` | the site loop's supervised bound | `[:1]` +4 | RED (test_inverter.py) |
+| 10 | `site_dev_bound` | `sum` + `any(None)` | `looks_frozen`, `rail_unreachable` | `[:1]` +4 | RED (test_inverter.py) |
+| 11 | `site_circulating_w` | `circulating_w` over measured power | SAFETY-31 trip | `[:1]` +4 | RED (test_watchdog.py) |
+| 12 | `inputs_ok` | `all` over both readings | gates the whole cycle (§11.1 rule 1) | `[:1]` +4 | RED (test_inverter.py) |
+| 13 | `units` | `tuple` of names | the arbiter's scope table | `[:1]` +4 | RED (5 files) |
+| 14 | `status_payload` | `min(_dues)` over `self.maints` | the operator's "maintenance due" row | `_dues[:1]` +4 | RED (test_maintenance.py) |
+| 15 | `maint_unit` | `self.inverters[self.maint_index]` | which pack the FSM drives | `[0]` −15 | RED (test_maintenance.py) |
+| 16 | store migration | the roster name list | MAINT-05's key migration | `[:1]` +4 | RED (test_maintenance.py) |
+| 17 | `validate_unit_ranges` | the roster argument | startup refusal | `[:1]` +4 | RED (test_inverter.py) |
+| 18 | `cycle()` stale-input hold | `any(sign_wd.tripped)` | **a latched unit's failsafe SET** | `[:1]` +4 | **was GREEN → now RED** (test_watchdog.py part 8) |
+| 19 | `publish()` status | `any(sign_wd.tripped)` | the MQTT status vocabulary | `[:1]` +4 | **was GREEN → now RED** (part 8) |
+| 20 | `status_payload()` banner | `any(sign_wd.tripped)` | the one headline on the page | `[:1]` +4 | **was GREEN → now RED** (part 8) |
+| 21 | `_grade_store_migration` | `any(sign_wd.tripped)` | SAFETY-02's re-arm guard | `[:1]` +4 | was GREEN → now RED (12j), see below |
+| 22 | `cycle()` undeliverable list | `sorted(...)` over shares | the *text* of one event line | `[:1]` +4 | **STILL GREEN — honest gap, below** |
+
+**Rows 18-20 are the finding, and they are not this card's code.** All three are
+`any(i.sign_wd.tripped for i in self.inverters)`, all three are SAFETY-30's, and
+all three survived a green 19-file suite for exactly the reason every blocker on
+this card survived: *the only fixture that reached them was a roster of ONE,
+where `self.inverters[:1]` IS `self.inverters`.* Part 3 of test_watchdog.py has
+built a two-inverter roster with only inverter B latched since SAFETY-30
+shipped — the precise data all three needed — and none of them read it.
+
+Row 18 is the one with teeth. A latched unit must take the whole roster past the
+stale-input hold, because that unit's `failsafe` SET is the thing parking it;
+main.py's own comment says *"the trip would stop acting the moment a poll was
+missed"*. With `[:1]`, a latched inverter B plus a one-cycle gap in inverter A's
+SoC returns early, and B's last share stands for the heartbeat to re-emit.
+test_watchdog.py part 8 now drives that with the latch at **each** position, plus
+the no-latch counterfactual that proves the hold really fires.
+
+**Row 21 — graded structurally, and argued to be redundant.** The `[:1]` there
+is now red on 12j's enumeration, but I could not construct a *reachable* state in
+which it changes an answer: `_grade_store_migration()` runs at startup, before
+any cycle, so a unit is tripped in memory only if its own `unit/<name>/sign_tripped`
+key was truthy — which makes `namespaced_latched` True and short-circuits the
+disjunct. I believe it is an equivalent mutant at that call site rather than a
+live hole, and I am recording the argument instead of asserting the conclusion.
+
+**Row 22 — STILL GREEN, and reported with its size.** `", ".join(sorted(u for u
+in resolution.shares if not self._can_write(u)))[:1]` truncates the **names in
+one event-log line**. It is +4 bytes and no check bites. The refusal itself —
+`elif {u for u in resolution.shares if not self._can_write(u)}` — is a different
+expression and *is* graded (test_peakguard.py part 10h-1b), so the site still
+stops; what a `[:1]` costs is an operator being told one name when two units have
+no writer. It is not a roster comprehension (it iterates `resolution.shares`), so
+12j does not cover it and does not pretend to. Closing it needs a three-inverter
+fixture with two writer-less entries, which is ALLOC-01's fixture and not this
+card's. **Filed as open, with its size and its consequence, rather than closed
+quietly or left unmentioned.**
+
+### And the family closed rather than the member
+
+`test_peakguard.py` part 12j enumerates the family from the AST and requires
+every member to take the roster **whole**, so a new reduction over a slice is red
+**on the line it is written**, at every roster length, with no fixture required.
+That check is what would have caught rounds 2, 3 and 4's blockers on the round
+they were written instead of one review round each; it is also what found rows
+18-21.
+
+⚠️ **AND IT WAS STILL TOO NARROW — see §4d.** Round 4's version enumerated the
+26 roster comprehensions inside the `Controller` class, because that is where
+the four known sites were. Round 5's blockers were four reductions in
+`validate.py`, one module over, over a list *derived* from the roster three
+calls away from it. The pin now parses every `.py` under `app/` and finds the
+roster by transitive closure from one option key: **183 reductions across 9
+modules.**
+
+## 4d. ⚠️ ROUND 5 — the same family one MODULE over, and an instrument that discovers its own scope
+
+Round 4 enumerated the family and closed it **inside the `Controller` class**,
+because that is where the four known sites lived. The review found four more
+survivors immediately, in `validate.py`, on a 19/19 green suite:
+
+| site | mutation | delta | suite |
+|---|---|---|---|
+| `validate.py:779` | `min(caps)` → `min(caps[:1])` | +4 B | **GREEN** |
+| `validate.py:779` | `min(caps)` → `min(caps[-1:])` | +5 B | **GREEN** |
+| `validate.py:778` | `caps = [cap for _, cap in caps_ix[:1]]` | +4 B | **GREEN** |
+| `validate.py:893` | `min(caps_ix[-1:], key=lambda p: p[1])` | +5 B | **GREEN** |
+
+**None of them is an equivalent mutant — a safety refusal disappears.** With
+`max_w: 5000` on inverter-a beside `2000` on inverter-b and
+`sign_disagree_w: 3000`, the shipped validator answers one problem —
+*"sign_disagree_w is 3000 W but max_w (inverter-b) is 2000 W, so the SAFETY-02
+sign-disagreement watchdog can never fire"* — and every one of the four answers
+**zero**. The site starts, with a watchdog reporting `armed` on the status page
+that cannot trip on pack B. That is rule 5's own failure mode reached **through**
+rule 5, which is the sentence `test_inverter.py:1657` says the rule exists to
+prevent. Rule 6 loses its refusal the same way.
+
+### Why round 4's pin could not see them, and why the fix is not four more checks
+
+`caps` and `caps_ix` are not comprehensions over `self.inverters`; they are lists
+**derived** from the roster, three function calls away from it, in a module the
+enumeration never opened. Closing them by hand would have produced a fifth
+rejection with the same shape one step over — that is the whole record of this
+card. **A hand-written scope is the same defect as a hand-written fixture**
+(MUTATION.md habit 12): a check whose data cannot reach the failure it names.
+
+### The instrument
+
+`test_peakguard.py` part 12j now parses **every `.py` under `app/`** off disk —
+no module is named anywhere in the check — and finds the roster by transitive
+closure from **one seed**, the `inverters` option key:
+
+* a function whose returns are roster-carrying is **roster-producing**
+  (`roster_entries` → `build_roster` → `unit_caps_indexed` → `unit_caps`);
+* a name assigned one carries it, **and so does a list accumulated in a loop
+  over one** — which is exactly what `caps`, `roster` and `problems` are, and
+  what round 4's rule could not express;
+* an attribute or property answering one carries it (`self.inverters`,
+  `Controller.packs`, `Controller.units`, `live_units()`);
+* **an argument at a call site taints that parameter in the callee**, which is
+  how the pin walks into `peakguard.binding_soc_floor`, `arbiter.resolve`,
+  `allocator.plan`, `circulation.circulating_w`, `maintenance.arbitrate` and
+  `store.migrate_maint_keys` without being told they exist;
+* and **a slice of a roster is still a roster**, so a mutation cannot cut the
+  taint and hide every reduction downstream of itself. An **index** is one unit
+  and is not.
+
+It then requires, at every place a roster-carrying value is reduced or iterated,
+that the whole of it arrives: no `[:1]`, `[-1:]`, `[:2]` or `[0]` between the
+roster and the reduction.
+
+### What it found — and the hand-written list was wrong in BOTH directions
+
+**183 reductions across 9 modules**, out of 23 `.py` files parsed:
+`main.py` 96, `allocator.py` 24, `validate.py` 19, `arbiter.py` 14,
+`circulation.py` 10, `maintenance.py` 10, `peakguard.py` 4, `inverter.py` 3,
+`store.py` 3 — and 14 modules with no roster reduction at all.
+
+The card's own suggested module list named `watchdog.py`, which reduces over no
+roster at all (SAFETY-30's sign watchdogs are strictly per-unit — there is
+nothing to slice), and did **not** name `maintenance.py` or `store.py`, which
+both do. A pin built from that list would have made a vacuous claim about one
+module and no claim at all about two others. That is the argument for computing
+the scope, made with data rather than with an assertion.
+
+The pin **independently rediscovers all four blockers** — it is told one option
+key and nothing else — and finds a **fifth** beside them at
+`validate.py:783`, the `min(caps_ix, key=...)` inside rule 5's message, which no
+review round named.
+
+### The counterfactual, at two depths
+
+* **Per site, all of them.** Every enumerated site's own expression, in its own
+  scope, mutated with each of the four cuts this card has actually been defeated
+  by. **183 sites × 4 cuts = 732** mutated spellings; every one reported. The same run asserts
+  the predicate **accepts** the legitimate wrapped forms the package really uses
+  (`enumerate`, `zip`, `sorted`, `pack_permissions(packs, floor)`) and does not
+  treat a keyed lookup (`weights[u]` in `allocator._fill`) as a slice — which is
+  what four false SLICED reports cost before `shortens()` was written.
+* **End to end, on the real files.** `[:1]` written into `app/validate.py` at
+  each blocker position, the **whole** analysis re-run over the mutated source,
+  and a sliced site required at that exact line — where the clean package
+  reports none. This is the check that would have taken PR #48 red four rounds
+  ago, with no fixture reaching it.
+
+### The sweep, and the number that must not be quoted alone
+
+All 183 sites were mutated to `[:1]`, one at a time, +4 bytes each, and each
+mutant run against the full 19-file suite in `goodwe-addon-ci` (mounted `:ro`,
+`python3 -B`, a fresh rsync per mutant; 0 `.pyc` in the tree before and after —
+a read-only mount cannot write one, so TEST-15 is closed by construction here
+rather than by discipline). **183 of 183 RED.**
+
+⚠️ **On its own that is tautological**: with the pin in the tree every slice is
+red *by the pin*. So all 51 mutants whose first red was `test_peakguard.py` were
+re-run with the pin **neutralised** (`_SLICED` blanked), leaving only the
+behavioural checks:
+
+| | |
+|---|---|
+| **145 of 183** | a behavioural fixture in this repository separates the site from a slice of itself — red with the pin turned off |
+| **38 of 183** | **nothing but this pin sees it.** Structurally closed by this card; behaviourally **UNGRADED**, and listed rather than counted as covered |
+
+The 38: `main.py` 27, `allocator.py` 6, `validate.py` 2, `arbiter.py` 1,
+`circulation.py` 1, `maintenance.py` 1. Grouped by what a `[:1]` there costs:
+
+* **The operator's page — 15, the largest group.** `Controller.checks`
+  (3310, 3311, 3319, 3328, 3330, 3347, 3368, 3370, 3400, 3458) and
+  `status_payload` (3556, 3566, 3578). A slice reports one unit's row where two
+  exist, or "1 of 2 live" reading 1 of 1. Nothing commands differently; what is
+  lost is the evidence a human uses to notice that it should.
+* **The write path's own counts.** `write_setpoint` 1267/1272/1280 — three
+  `len(targets)` guards. The write itself iterates `targets` at 1287 and *is*
+  graded (test_inverter.py); these three are its log arithmetic and refusal
+  count.
+* **The allocator's internals.** `_fill`'s zero-weight last-resort pool (365),
+  `plan`'s `dropped` (526, 653), `free` (584), `frac_order` (591). ALLOC-01
+  drives two and three units through the *weighted* pass; the last-resort pass
+  and the largest-remainder tie-break are reached, but not with enough units for
+  a slice to change the answer.
+* **Startup and FSM plumbing.** `__init__` 235/351, `_only` 831,
+  `_maint_button` 805, `cycle`'s maintenance zip 1505, `send_heartbeats` 3015,
+  `check_output_clamp` 2445/2452, `check_circulating` 2701,
+  `maintenance.arbitrate` 547, `arbiter.site_resolve` 517,
+  `circulation.opposing` 242.
+* **Two refusal-TEXT sites.** `validate._roster_problems`'s `len(entries)` (554)
+  and `refuse()`'s numbering loop (1263) — both shape the words of a refusal
+  that still happens.
+* **`_grade_store_migration` (698)**, already row 21 of §4c, argued there to be
+  an equivalent mutant at that call site. The argument is unchanged and is still
+  an argument, not a proof.
+
+⚠️ **None of the 38 is closed behaviourally by this card, and saying so is the
+point.** Closing sites one at a time is what cost this card four review rounds.
+The pin closes the **family** — a slice at any of them is red on the line it is
+written — and this list is what a shape pin can never promise.
+
+### And the behavioural half, because a shape pin cannot grade a meaning
+
+The pin grades an **identity** ("the whole roster arrives"). `min` → `max` is a
+zero-byte edit and invisible to it, forever. So `test_validate.py` grows a
+**roster SET** for the three rules that reduce over `unit_caps_indexed()`:
+rosters of width 2, 3, 4 and 5 with the one small cap at **every position** —
+14 rosters × 3 rules = 42 runs of the real validator — plus a **computed family
+table** of twelve candidate reductions (`max`, `first`, `last`, the mean, and
+`[:1]`, `[-1:]`, `[:2]`, `[:3]`, `[1:]`, `[:-1]`, `[::2]`) each compared against
+what the shipped validator actually said on the same roster. Only `min` agrees
+everywhere; any member no roster kills is **printed as a named survivor** and
+takes the check red.
+
+### ⚠️ A THIRD RULE WAS READING THE FLAT `max_w`, AND IT IS SAFETY-30's
+
+Found by reading the three branches side by side — **not** by the pin, and said
+that way because it is the shape of what the pin cannot see. Rule 5's sibling
+branch, `unit_sign_disagree_w` (SAFETY-30's per-inverter sign watchdog), was
+graded against `_number(opts, "max_w", 2000.0)` — the **flat** option — three
+lines under a branch that had already stopped doing that. Both directions were
+measured before the fix:
+
+* a roster of two 2000 W units beside a leftover `max_w: 5000` from a
+  single-inverter install, with `unit_sign_disagree_w: 3000`, produced **zero
+  problems**. The site started, the status page said `armed`, and the per-unit
+  watchdog could not trip on **either** unit. Identical sentence to the blocker,
+  reached through the branch beside it;
+* and a roster of two 5000 W units with no flat key was **refused** at 3000 W
+  against a 2000 W *default the operator never wrote*, for a threshold both
+  units can reach.
+
+It takes the same `weakest` the branch above takes, from the same list, and
+names the same unit. At a roster of one `unit_caps()` is `[max_w]`, so the
+shipped single-inverter refusal is the same comparison, the same boundary and
+the same sentence. Both directions are asserted in `test_validate.py`.
+
+### ⚠️ WHAT THE PIN CANNOT SEE — open rows, with sizes
+
+1. **Semantics.** `min` vs `max` vs the mean: zero-byte edits, invisible to any
+   shape pin. Only the behavioural sets above can see them, and they only see
+   the rules they drive.
+2. **Direct index sites that are not reductions.** `self.inverters[0]` in
+   `_only()` and `actuator_of()`, `self.inverters[self.maint_index]` in
+   `maint_unit`, `entries[index]` in `_unit_label()`. Single-unit lookups, meant
+   to be, graded where they live.
+3. **A subscript by a NAME.** `weights[u]`, `cap[u]`, `add[u]` in
+   `allocator._fill` are keyed lookups into a roster-derived mapping and are
+   accepted deliberately, so `caps[i]` with a variable `i` would pass. Not in
+   the family this card has been defeated by; buying it costs four false reports.
+4. **A slice through an intermediate call.** `sorted(roster)[:1]` subscripts a
+   call result, not a roster reference. Nothing in `app/` is written that way
+   today; if something is, it would not be seen.
+5. **Anything outside `app/`.** `tools/`, `sim/` and the checks themselves are
+   not parsed — and `sim/inject.py` reaches `validate_startup_config()`.
+6. **The taint's own seam.** It crosses a call boundary only where the callee is
+   a plain function this package defines and the argument is positional or
+   keyword. A roster handed through `*args`, stored in a dict and read back, or
+   passed to a method on an unresolvable object, is lost at that hop — and
+   everything downstream goes **unenumerated** rather than reported unreachable.
+   That is the shape of the remaining exposure: not zero, and not measurable
+   from inside the check.
+7. **`cycle()`'s undeliverable-unit log line** (row 22 of §4c) is still green at
+   +4 bytes, unchanged from round 4 and still filed open.
+
+## 5. ⚠️ THE RESIDUAL — a per-pack EMS floor is NOT this card
+
+`peak_soc_floor` is still **one number for the site**, so the card's own
+"or the deeper pack is needlessly withheld" half is not closed and this record
+does not pretend it is. With cut-outs of 10 % and 18 %, rule 8 obliges the
+operator to set the EMS floor above 18, and the 10 % pack is then held above its
+own need. Closing that means `peak_soc_floor` becoming a per-entry key too, which
+is a second option migration and a product decision about what the site-wide
+number then means. The card scoped itself to `bms_soc_floor` and explicitly told
+this developer not to widen it, so it is filed here as the open question it is
+rather than smuggled in.
+
+**Also still not in this card, and named by the shipped code already:** the
+charge *ceiling* is the mirror image — `pack_floor_soc` is the wrong reduction
+for it, because a ceiling is the **fullest** pack and `arbitrage`'s `soc_ceiling`
+takes one number. `main.py:932-936` says so, and it belongs to CFG-04/SPIKE-04's
+per-pack bound. Nothing here touched it.
+
+## 6. What was changed, and one thing that was found on the way
+
+* `config.yaml` — `bms_soc_floor: int(0,50)` required per `inverters:` entry;
+  the flat key and its default are untouched and are documented as the
+  single-inverter shape's own cut-out.
+* `app/inverter.py` — `Inverter.bms_soc_floor`; `_entry_bms_floor()` (`None`, not
+  a borrowed number and not `0.0`); `_flat_bms_floor()`.
+* `app/peakguard.py` — `Pack`, `pack_floor_pct()`, `pack_permissions()`,
+  `binding_soc_floor()`. `discharge_permitted()` is unchanged and is still the
+  one place the question is answered.
+* `app/validate.py` — `unit_bms_floors_indexed()`; rule 8 grades every unit and
+  names it via the **roster** index the value came off.
+* `app/main.py` — `Controller.packs`; the `decide(soc_floor=…)` reduction; the
+  floor-limited notification names the pack(s) at or below their own floor, at a
+  roster of two or more only.
+* `tools/supervisor_shape_probe.py` — **re-run, and repaired.** MUTATION.md
+  habit 8: a committed transcript is a check and it decays. Making the key
+  required broke §C outright and, worse, left §D printing **PASS** on a refusal
+  about the *wrong key* — its "no `max_w`" case was answered `Missing option
+  'bms_soc_floor'`. §D is now an isolated counterfactual over a **merged,
+  accepted** baseline with exactly one key varied per case, asserting the key's
+  **name** in the refusal, and it carries a `bms_soc_floor` case in both
+  directions. Re-run against `ghcr.io/home-assistant/amd64-hassio-supervisor:2026.08.0`:
+  `all cases passed`.
+* `app/inverter.py`, found by the mutation battery — `_flat_bms_floor()` was
+  written with the default in **two** places (the `.get()` fallback *and* the
+  blank test). Deleting either one survived, because each covered for the other:
+  MUTATION.md's masking section in three lines of option reading. It has one
+  defaulting line now, and M12 takes six checks red.
+
+* **Round 3 changed no `app/` file at all.** `test_peakguard.py` only:
+  parts 12c2 and 12g. Its battery was **46 mutations across
+  `binding_soc_floor()`'s reduction, the `decide()` call site, `Controller.packs`
+  and `pack_floor_pct()`'s conjunction** — bytecode purged and counted before and
+  after each (23 → 0). **43 red, 3 survivors, all three recorded above and in the
+  in-process rows**: `max(floors[:12])` and `max(floors[-12:])`, which need a
+  13-pack roster to observe and are reported with that size rather than hidden;
+  and `max(set(floors))`, which is **equivalent** — `max` is duplicate-invariant,
+  so it cannot change an answer. `list(reversed(self.packs))` is equivalent too
+  (`max` is order-invariant) and is nonetheless red on the structural pin.
+
+⚠️ **No measurement of inverter B appears anywhere in this change.** It does not
+physically exist. Every second-pack number in a fixture, in the probe and in
+config.yaml's commented example is **simulated and labelled as such**; only the
+10 % on inverter A is read off hardware. The three-pack runs added in round 3 are simulated
+twice over: there is no inverter C at all, and the shallow slots carry inverter
+A's measured 10 % while the 35 % cut-out that moves along the roster is invented.
+
+---
+
+## 7. The probe transcript, re-run 2026-09-05 on 2026.08.0
+
+Command (unchanged, in `tools/supervisor_shape_probe.py`'s own docstring):
+
+```
+    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
+```
+
+It reads `config.yaml` and runs Supervisor's own `AppOptions` validator in a
+throwaway container. It touches no live Supervisor, POSTs nothing and installs
+nothing.
+
+⚠️ **RE-RUN AGAIN ON 2026-09-05**, because the rebase onto `67e649a` merged
+SPIKE-04a's `max_w: 4600` into the same §C/§D blocks this card had rewritten,
+and MUTATION.md habit 8 says a committed transcript that a document quotes is a
+check. A hand-merged transcript is not a measurement of anything. The block
+below is the output of that run, not of the 2026-09-04 one: B's rating reads
+**4600** — its datasheet figure, still not a measurement of any unit — and every
+case still passes.
+
+```
+== C. AC2: a two-inverter blob an operator would POST ==
+  PASS  two inverters
+        [{"name": "inverter-a", "setpoint_entity": "number.goodwe_a_setpoint_w", "soc_entity": "sensor.goodwe_a_soc", "batt_entity": "sensor.goodwe_a_battery_power", "max_w": 5000, "bms_soc_floor": 10}, {"name": "inverter-b", "setpoint_entity": "number.goodwe_b_setpoint_w", "soc_entity": "sensor.goodwe_b_so
+
+== D. what the schema itself refuses, per entry ==
+  PASS  the per-entry BASELINE is ACCEPTED, so every refusal below has nowhere else to come from
+        [{"name": "inverter-b", "setpoint_entity": "number.b", "max_w": 4600, "bms_soc_floor": 10}]
+  PASS  an entry with no name is refused, and the refusal NAMES it
+        Missing option 'name' in inverters in GoodWe RS485 Controller (local_goodwe_controller)
+  PASS  an entry with no setpoint_entity is refused, and the refusal NAMES it
+        Missing option 'setpoint_entity' in inverters in GoodWe RS485 Controller (local_goodwe_controller)
+  PASS  an entry with no max_w is refused, and the refusal NAMES it
+        Missing option 'max_w' in inverters in GoodWe RS485 Controller (local_goodwe_controller)
+  PASS  an entry with no bms_soc_floor (SAFETY-32) is refused, and the refusal NAMES it
+        Missing option 'bms_soc_floor' in inverters in GoodWe RS485 Controller (local_goodwe_controller)
+  PASS  an entry with max_w over the range is refused, and the refusal NAMES it
+        value must be at most 5000.0
+  PASS  an entry with bms_soc_floor over the range (SAFETY-32) is refused, and the refusal NAMES it
+        value must be at most 50.0
+  PASS  a JSON STRING where the list belongs is refused
+        Invalid list for option 'inverters' in GoodWe RS485 Controller (local_goodwe_controller)
+
+== E. the ROLLBACK direction, and the operator's UI ==
+  PASS  a schema WITHOUT `inverters` drops the key with a warning rather than refusing - so a downgrade is not the §B trap in reverse
+        ['arbitrage_enabled', 'arbitrage_soc_ceiling', 'arbitrage_soc_floor', 'auto_start', 'batt_entity', 'batt_invert']
+  PASS  Supervisor's UI renderer turns it into a repeatable section rather than choking - an operator can add the second inverter in the Configuration tab, which the JSON-string alternative could not offer
+        [{"name": "inverters", "type": "schema", "optional": true, "multiple": true, "schema": [{"name": "name", "required": true, "type": "string"}, {"name": "setpoint_entity", "required": true, "type": "string"}, {"name": "max_w", "lengthMin": 100.0, "lengthMax": 5000.0, "required": true, "type": "integer
+
+== all cases passed ==
+```

goodwe_controller/DOCS.md

@@ -78,9 +78,20 @@ inverters:
     setpoint_entity: number.goodwe_b_setpoint_w
     soc_entity: sensor.goodwe_b_soc
     batt_entity: sensor.goodwe_b_battery_power
-    max_w: 3000
+    max_w: 4600
 ```
 
+⚠️ **The 4600 W is inverter B's *datasheet* figure, not a measured one.** B is a
+GoodWe GW5048D-ES (serial `55048ESU22AW0992`, identified 2026-09-04) whose
+datasheet gives max charging and discharging power as 4600 W; with nothing
+connected to its PV inputs the battery path is the ceiling, not the 5000 VA AC
+nameplate. The datasheet prints that number under *Battery Input Data*, so it
+may be a DC figure, while `max_w` is graded against register `0x0518` — the
+inverter's own **AC** power. If it is DC the AC-side ceiling is nearer 4324 W.
+`max_w: 4600` is still the right thing to configure, because the freeze rail is
+`min(max_w, dev_max)` and the device range read off the unit is what binds.
+`goodwe/NOTES.md` §1.1b records both readings and picks neither.
+
 | per-entry key | required | meaning |
 |---|---|---|
 | `name` | yes | Short identifier. It namespaces this unit's SAFETY-02 latch, heartbeat and write bookkeeping in the add-on's state file, so **two units may not share one** |
@@ -554,7 +565,7 @@ help - see "Why the tuning is what it is".
 | `peak_forecast_entity` | Quarter-hour demand forecast, for capacity-tariff markets. Empty = no cap |
 | `peak_cap_w` | The site's capacity-tariff target |
 | `peak_soc_floor` (20) | **The percent below which the capacity-peak guard will not discharge the battery.** ⚠️ It bounds **the peak guard only** — it is **not a pack-wide reserve**, and ordinary self-consumption discharges straight past it (SAFETY-25, see below). Not optional and not the same thing as `maintenance_soc_floor` |
-| `bms_soc_floor` (10) | The pack's **own** cut-out percent, the number the BMS enforces whatever you set above. `peak_soc_floor` must be **strictly above** it or the add-on refuses to start |
+| `bms_soc_floor` (10) | The pack's **own** cut-out percent, the number the BMS enforces whatever you set above. `peak_soc_floor` must be **strictly above** it or the add-on refuses to start. ⚠️ **At a declared `inverters:` roster this key moves INTO each entry and is REQUIRED there** (SAFETY-32): it describes a battery, and two packs of different models have different cut-outs, so one number for both protects the shallower pack with the deeper pack's BMS. Nothing is inherited — an entry that omits it is refused **by name** at startup, and the flat key below is then not read at all |
 | `price_now_entity`, `price_avg_entity` | Dynamic tariff. Empty = never force a paid grid top-up |
 
 On a capacity-tariff site the maintenance charge is capped by the headroom left

goodwe_controller/MUTATION.md

@@ -300,6 +300,69 @@ Cheap habits fall out of it, and all of them are now used in this repository:
    assert the **shape** of that second report, not only its verdict, so the
    check cannot silently revert to grading the first path.
 
+10. **A fixture of N members cannot separate two reductions that agree on N
+    members — so grade the FAMILY, and grade it from the SOURCE.** This is the
+    only lesson SAFETY-32 cost four review rounds to learn, and it generalises
+    past packs to every roster, list and window in this repository. Two packs
+    cannot tell `max` from `min` from first from last. Three cannot tell `max`
+    from `max(x[-2:])`. **The regress does not terminate in a fixture**: `[:1]`
+    needs two members, `[:2]` three, `[:3]` four, and adding one more member
+    moves the hole rather than closing it. Three things follow, and all three
+    are now in `test_peakguard.py` parts 12c2, 12g, 12i and 12j:
+    * the fixture is a **SET** — the extreme at every position of the roster,
+      not one roster with the extreme somewhere;
+    * the family table is **COMPUTED and PRINTED**, so a member no fixture kills
+      shows up as a named survivor and takes the check red, instead of being
+      absent from a list nobody re-derived;
+    * where the claim is an **IDENTITY** ("this roster", "this list"), pin it
+      **exactly on the AST** — `ast.unparse(arg) == "self.packs"` is false of
+      every slice, where `"self.packs" in src` is true of all of them. Where the
+      claim is **SEMANTIC** ("the maximum"), a shape pin would refuse honest
+      refactors, so report the unreached width **with its size** instead.
+
+11. **When a check of this shape is found, mutate its SIBLINGS before shipping
+    the fix.** SAFETY-32 was rejected three times for the same defect one step
+    over: the reduction, then the roster handed to it, then the reduction handed
+    to the *other argument of the same call*. Enumerating the family from the
+    AST and mutating each member took one afternoon and found **four more
+    survivors in code the card never touched** — three of SAFETY-30's
+    `any(i.sign_wd.tripped for i in self.inverters)` reductions, invisible
+    because the only fixture that reached them was a roster of ONE, where
+    `self.inverters[:1]` **is** `self.inverters`. Ask of every fix: *what is the
+    sibling of the thing I just hardened, and does any fixture separate it from
+    a slice of itself?*
+
+12. **When the same shape has been found twice, STOP CLOSING SITES AND BUILD
+    THE INSTRUMENT — and make it DISCOVER its own scope.** SAFETY-32 was
+    rejected four times, and each round closed exactly the site it was handed:
+    the reduction, then the roster handed to it, then the *sibling argument* of
+    the same call, then the same family one *module* over, in validate.py.
+    Round 4 did enumerate — and enumerated inside the `Controller` class,
+    because that is where the four known sites lived. **A hand-written scope is
+    the same defect as a hand-written fixture**: it is a check whose data cannot
+    reach the failure it names, and it goes on passing while the thing it was
+    supposed to cover sits in the file nobody added to the list. Round 5's pin
+    parses every `.py` under `app/`, seeds itself from ONE option key, and
+    propagates through returns, accumulator loops, attributes and *call
+    arguments* to find the roster wherever it went — 183 reductions across 9
+    modules. It rediscovered all four blockers without being told where to look,
+    and it named two modules the hand-written list would not have contained
+    (`maintenance.py`, `store.py`) while *omitting* one the list did contain
+    (`watchdog.py`, which is strictly per-unit and reduces over no roster at
+    all). **The list was wrong in both directions**, which is exactly what a
+    computed scope is for.
+
+13. **Say what the instrument CANNOT see, with sizes, in the same breath.** A
+    structural pin grades an **identity** ("this whole roster arrives"); it can
+    never grade a **meaning** (`min` vs `max` is a zero-byte edit and invisible
+    to it). Ship the pin AND the behavioural set, name the gap, and give every
+    unreached case its byte delta — `cycle()`'s undeliverable-unit log line
+    (+4 B, still green), a subscript by a *variable* rather than a constant, a
+    slice taken through an intermediate call, anything outside `app/`. **An
+    enumerated list with an honest gap is worth more than a claim of
+    completeness a reviewer falsifies in ten minutes**, and every round of this
+    card that claimed the latter was rejected for it.
+
 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

goodwe_controller/app/inverter.py

@@ -15,6 +15,11 @@ The scalars, and what each one was silently asserting:
                           SAFETY-24's pack floor and arbitrage's bounds. An
                           average lets the emptier pack be driven below its own
                           floor; a maximum parks the fuller one.
+  `bms_soc_floor`         SAFETY-32. ONE cut-out percent for every pack, and it
+                          describes A BATTERY. Two packs of different models
+                          have different cut-outs, so the flat key graded the
+                          shallower pack against the deeper one's BMS - wrong
+                          in the direction that empties a pack.
   `batt`                  ONE battery power into the anti-windup saturation
                           detector - see the SITE/UNIT note at the bottom of
                           this docstring, because this one goes the OTHER WAY.
@@ -117,6 +122,12 @@ import math
 from datetime import datetime
 
 from .clamp import ClampResult
+# CFG-03's ONE in-code mirror of config.yaml's SAFETY-24 defaults. Imported
+# rather than retyped: the flat-keys path below needs `bms_soc_floor`'s
+# shipped default and a literal here would be the fourth defaults site that
+# ticket exists to prevent. peakguard imports arbiter/control/tariff and none
+# of those imports this module, so the direction is one-way.
+from .peakguard import PEAK_OPTION_DEFAULTS
 from .store import unit_key
 from .watchdog import SignWatchdog, SignWatchdogConfig
 
@@ -170,7 +181,7 @@ class Inverter:
 
     def __init__(self, name, *, setpoint_entity="", soc_entity="",
                  batt_entity="", batt_invert=False, max_w=2000.0,
-                 store=None, sign_cfg=None):
+                 bms_soc_floor=None, store=None, sign_cfg=None):
         self.name = str(name)
         self.setpoint_entity = str(setpoint_entity or "")
         self.soc_entity = str(soc_entity or "")
@@ -179,6 +190,19 @@ class Inverter:
         # The supervised cap on what may be written to THIS setpoint entity.
         # See the module docstring on why this is a number and not a `Tuning`.
         self.max_w = float(max_w)
+        # SAFETY-32. THIS PACK'S OWN BMS CUT-OUT, in percent, or None when the
+        # roster entry did not state one.
+        #
+        # ⚠️ NOT DEFAULTED HERE, AND None RATHER THAN A NUMBER. A cut-out is a
+        # property of the battery in the cupboard; inventing one for a pack that
+        # did not state it is precisely this card's defect - a pack graded
+        # against a floor that belongs to a different battery - rebuilt in the
+        # constructor. `peakguard.pack_floor_pct()` treats None as an unknown
+        # floor and `discharge_permitted()` treats an unknown floor as NO
+        # permission, so the absence costs a shave; validate.py rule 8 refuses
+        # the config by name long before that, at startup.
+        self.bms_soc_floor = (None if bms_soc_floor is None
+                              else float(bms_soc_floor))
 
         # --- the device's own reported range, read from its own entity -------
         # None until `hass.limits()` has answered. NOT guessed at: ESPHome is
@@ -339,8 +363,9 @@ def build_roster(opts: dict, store, sign_cfg=None) -> list:
     TWO SHAPES, AND WHICH ONE IS IN FORCE IS DECIDED BY ONE TEST: is
     `inverters:` empty?
 
-      EMPTY   the five flat keys - `setpoint_entity`, `soc_entity`,
-              `batt_entity`, `batt_invert`, `max_w` - describe the ONE inverter,
+      EMPTY   the six flat keys - `setpoint_entity`, `soc_entity`,
+              `batt_entity`, `batt_invert`, `max_w`, `bms_soc_floor` (SAFETY-32)
+              - describe the ONE inverter,
               exactly as the shipped scalars did. This is what every install
               that upgrades into this version reads, without an operator
               touching anything, and it is byte-identical to what DEV-02
@@ -353,8 +378,8 @@ def build_roster(opts: dict, store, sign_cfg=None) -> list:
               `soc_entity` has no SoC sensor; it does NOT borrow the flat one,
               because "this unit's number came from somewhere else" is the
               defect DEV-02 spent a card removing and a fallback here would
-              rebuild it in three lines. `name`, `setpoint_entity` and `max_w`
-              are required of every entry - the schema enforces it on the
+              rebuild it in three lines. `name`, `setpoint_entity`, `max_w` and
+              `bms_soc_floor` (SAFETY-32) are required of every entry - the schema enforces it on the
               Supervisor path, `validate.py` rule 9 enforces it for sim/inject.py
               and the checks, which reach this function with any dict at all.
 
@@ -380,6 +405,12 @@ def build_roster(opts: dict, store, sign_cfg=None) -> list:
             batt_entity=opts.get("batt_entity", ""),
             batt_invert=bool(opts.get("batt_invert")),
             max_w=float(opts.get("max_w", 2000)),
+            # SAFETY-32. THE FLAT KEY, because this IS the single-inverter shape
+            # - the one pack the flat options describe is the one pack whose
+            # cut-out `bms_soc_floor` states. Defaulted from CFG-03's single
+            # mirror exactly as validate.py rule 8 defaults it, so an install
+            # that never set the key reads the same 10 % in both places.
+            bms_soc_floor=_flat_bms_floor(opts),
             store=store, sign_cfg=sign_cfg)]
 
     roster = []
@@ -401,10 +432,54 @@ def build_roster(opts: dict, store, sign_cfg=None) -> list:
             # ⚠️ NOT `opts["max_w"]`. See the docstring: a rating an entry did
             # not state is not the flat one, it is a rating rule 9 refuses.
             max_w=_entry_max_w(entry),
+            # ⚠️ NOT `opts["bms_soc_floor"]`, FOR `max_w`'S REASON AND THIS
+            # CARD'S. An entry that omits its cut-out has NOT got the flat one;
+            # it has none, and rule 8 refuses it by name. Borrowing here would be
+            # SAFETY-32's own defect written in three lines - the shallower pack
+            # graded against the deeper pack's BMS.
+            bms_soc_floor=_entry_bms_floor(entry),
             store=store, sign_cfg=sign_cfg))
     return roster
 
 
+def _flat_bms_floor(opts: dict):
+    """The single-inverter shape's own cut-out, or None if it is unparseable.
+
+    Defaulted from `PEAK_OPTION_DEFAULTS` when the key is absent or blank, which
+    is `validate._number()`'s behaviour on the same key - the two have to agree
+    or the validator would grade a number the roster does not build.
+    """
+    # ⚠️ ONE defaulting line, not two. The first cut wrote the fallback into the
+    # `.get()` AND into the blank test below it, and a mutation that deleted
+    # either one survived - each was covering for the other, which is
+    # MUTATION.md's masking section in three lines of configuration reading.
+    raw = opts.get("bms_soc_floor")
+    if raw is None or raw == "":
+        return float(PEAK_OPTION_DEFAULTS["bms_soc_floor"])
+    try:
+        return float(raw)
+    except (TypeError, ValueError):
+        return None
+
+
+def _entry_bms_floor(entry: dict):
+    """One entry's OWN cut-out, or None when it did not state a usable one.
+
+    None rather than a borrowed number and rather than 0.0 - `_entry_max_w()`
+    can answer 0.0 because a zero rating commands nothing, but a zero FLOOR is
+    the most permissive value the key has and would read as "this pack may be
+    emptied". Rule 8 refuses the missing key by name; until it does, None
+    withholds.
+    """
+    raw = entry.get("bms_soc_floor")
+    if raw is None or raw == "":
+        return None
+    try:
+        return float(raw)
+    except (TypeError, ValueError):
+        return None
+
+
 def _entry_max_w(entry: dict) -> float:
     """One entry's supervised cap, or 0.0 when it did not state a usable one.
 

goodwe_controller/app/main.py

@@ -1065,6 +1065,26 @@ class Controller:
             return None
         return float(min(float(v) for v in vals))
 
+    @property
+    def packs(self) -> list:
+        """SAFETY-32. Each pack as its own THREE numbers, in roster order.
+
+        `pack_floor_soc` above is the site's ONE verdict and stays exactly what
+        DEV-02 made it - the emptiest measured pack. This is the thing that
+        reduction cannot produce: by the time `min()` has answered, WHICH pack
+        the number came from and how far that pack was from ITS OWN cut-out have
+        both been thrown away, and two packs at 15 % against cut-outs of 10 % and
+        20 % have opposite answers that are indistinguishable afterwards.
+
+        ⚠️ EVERY unit, live or not. Same reason as `inputs_ok`: a pack whose SoC
+        did not answer is a pack nothing can grade, and dropping it from this
+        list would let the site spend the packs that DID answer while one sat
+        unmeasured. `peakguard.discharge_permitted()` treats a None SoC as no
+        permission, which is where that must be decided.
+        """
+        return [peakguard.Pack(inv.name, inv.soc, inv.bms_soc_floor)
+                for inv in self.inverters]
+
     @property
     def inputs_ok(self) -> bool:
         """The site meter, and EVERY pack's own two readings.
@@ -1881,9 +1901,21 @@ class Controller:
             # protect. None stays None: `decide()` treats it as floor-limited,
             # which costs a shave rather than a pack.
             soc=self.pack_floor_soc,
-            soc_floor=float(self.o.get(
+            # ⚠️ SAFETY-32. THE SAME OPTION, REDUCED OVER THE PACKS' OWN
+            # CUT-OUTS. `peak_soc_floor` is still one site-wide EMS floor and is
+            # still read from that one key with CFG-03's one mirror behind it;
+            # what `binding_soc_floor()` adds is the conjunction with each pack's
+            # OWN `bms_soc_floor`, so the floor this site is graded against can
+            # never be below the deepest cut-out on the roster. MAXIMUM here
+            # pairs with the MINIMUM in `pack_floor_soc`: both reductions move
+            # the verdict towards refusing a shave and away from spending a pack.
+            # Under any config rule 8 accepts it IS the option, for every pack -
+            # asserted over the whole schema range in test_peakguard.py part 12
+            # rather than assumed, because "another rule refuses that" is a claim
+            # about rule ordering and sim/inject.py does not run rule 8 at all.
+            soc_floor=peakguard.binding_soc_floor(self.packs, float(self.o.get(
                 "peak_soc_floor",
-                peakguard.PEAK_OPTION_DEFAULTS["peak_soc_floor"])),
+                peakguard.PEAK_OPTION_DEFAULTS["peak_soc_floor"]))),
             max_hold_s=self.p1.averager.max_hold_s,
             # ⚠️ SAFETY-20. The device range goes in TOO, and this call site is
             # the one that needed it most: `standing` is `last_write`, i.e. the
@@ -2596,6 +2628,22 @@ class Controller:
         # notification that matters into a traceback.
         _at_floor = ("at the floor" if g.soc_floor is None
                      else f"at {float(g.soc_floor):.0f} %")
+        # ⚠️ SAFETY-32. WHICH PACK STOPPED THE SITE. `g.soc_floor` is the floor
+        # the decision was actually taken with, so this re-grades nothing and
+        # cannot disagree with the alarm it is printed inside. At a roster of one
+        # the sentence is omitted entirely and this notification is byte-for-byte
+        # what SAFETY-25 shipped - there is exactly one pack and naming it would
+        # be noise on every existing install.
+        _blocked = [name for name, why
+                    in peakguard.pack_permissions(self.packs, g.soc_floor)
+                    if why is not None]
+        _which = ("" if len(self.inverters) < 2 else
+                  f"\n\nSAFETY-32 - WHICH PACK: this is graded per pack against "
+                  f"that pack's own BMS cut-out (bms_soc_floor), and the "
+                  f"pack(s) at or below their own floor right now are "
+                  f"{', '.join(_blocked) if _blocked else '(none - see the reason above)'}"
+                  f". The other packs on the roster are not the reason the guard "
+                  f"stopped and raising their cut-out will not change this.")
         await self.hass.call("persistent_notification", "create", {
             "notification_id": "goodwe_peak_soc_floor",
             "title": "GoodWe: the capacity-peak guard has run out of battery",
@@ -2615,7 +2663,7 @@ class Controller:
                 f"{_at_floor} - ordinary self-consumption has no SoC "
                 f"floor at all and will go on discharging past it, down to the "
                 f"pack's own BMS cut-out. What has stopped is the guard buying "
-                f"you a lower bill, not the pack being spent."),
+                f"you a lower bill, not the pack being spent." + _which),
         })
 
     async def check_circulating(self) -> None:

goodwe_controller/app/peakguard.py

@@ -360,6 +360,29 @@ distinction in DOCS.md and in this comment. Revisit if a THIRD floor appears -
 a loop-side guard would be the third - at which point the migration buys enough
 to be worth its cost.
 
+------------------------------------------------------------------------------
+SAFETY-32: ONE `bms_soc_floor` FOR TWO PACKS GRADES ONE AGAINST THE OTHER'S BMS
+
+`bms_soc_floor` above describes A PACK, not a site, and it was a flat option
+because there was one pack. At two, two batteries of different models have
+different cut-outs, and one number for both is wrong in the direction that
+empties a battery: the SHALLOWER pack (the higher cut-out) is protected by a
+floor that belongs to the DEEPER one. So it became a roster key - `Pack` carries
+each unit's own value, `pack_floor_pct()` conjoins it with the site's EMS floor,
+and validate.py rule 8 grades EVERY unit and NAMES the one it refuses.
+
+⚠️ `peak_soc_floor` DID NOT MOVE, AND THE RESIDUAL IS RECORDED RATHER THAN
+HIDDEN. It is one number for the site, so with cut-outs of 10 % and 18 % the
+operator must set it above 18 and the deeper pack is then withheld above its own
+need. That half - a per-pack EMS floor - is NOT this card and must not be
+smuggled in with it; DECISIONS/SAFETY-32-per-pack-bms-floor.md states it as the
+open question it is.
+
+⚠️ AND THE MIN() OVER MEASURED SoC IS STILL RIGHT. `Controller.pack_floor_soc`
+reduces to the emptiest pack and this card does not touch it. What changed is
+the FLOOR it is graded against, and the addition of a per-pack answer beside the
+site's one verdict - see `pack_permissions()`.
+
 ------------------------------------------------------------------------------
 AND IT READS NO PER-PHASE QUANTITY, ON PURPOSE
 
@@ -572,6 +595,110 @@ def discharge_permitted(soc, soc_floor) -> str | None:
     return None
 
 
+@dataclass(frozen=True)
+class Pack:
+    """SAFETY-32. ONE pack's three numbers for the floor question, NAMED.
+
+    `name`       the roster name, because a refusal that does not say WHICH pack
+                 stopped the site sends an operator to the wrong device - the
+                 same defect CFG-04's `unit_caps_indexed()` was written for.
+    `soc`        THIS pack's measured state of charge. None when its sensor did
+                 not answer, and None is not a full battery.
+    `bms_floor`  THIS pack's OWN cut-out percent (`bms_soc_floor`), which is a
+                 property of the hardware in the cupboard and NOT of the site.
+                 None when the roster entry did not state one - see
+                 `pack_floor_pct()` for why that is withheld and not 0 %.
+
+    ⚠️ IT CARRIES THE CUT-OUT, NOT THE EMS FLOOR. `peak_soc_floor` is one number
+    for the whole site (the depth a money-saving discharge may never reach) and
+    stays a flat option; `bms_soc_floor` describes a battery and became a roster
+    key here, because two packs of different models have different cut-outs and
+    grading both against one of them is wrong in the direction that empties the
+    shallower one.
+    """
+
+    name: str
+    soc: float | None
+    bms_floor: float | None
+
+
+def pack_floor_pct(pack, soc_floor):
+    """The percent THIS pack may not be spent below, or None if that is unknown.
+
+    `max(the site's EMS floor, this pack's own cut-out)` - the CONJUNCTION, and
+    the direction matters: the EMS floor is what the operator asked for and the
+    cut-out is what the hardware will do anyway, so a pack is protected by
+    whichever is higher. Taking the site floor alone is the shipped defect this
+    card removes (the shallower pack graded against the deeper one's cut-out);
+    taking the cut-out alone would throw SAFETY-24's margin away.
+
+    ⚠️ AN UNSTATED CUT-OUT IS None, NOT ZERO, AND NOT THE FLAT OPTION. 0 % would
+    be a floor that permits everything - the most permissive value there is,
+    invented from an absence - and borrowing the flat `bms_soc_floor` is CFG-04's
+    "nothing is inherited" broken in one line, which is this card's whole subject
+    restated. `discharge_permitted()` already treats a None floor as NO
+    permission, so an entry that forgot the key costs a shave rather than a pack.
+
+    ⚠️ AND UNDER A rule-8-VALID CONFIG THIS IS `soc_floor`, FOR EVERY PACK.
+    validate.py rule 8 refuses `peak_soc_floor <= bms_soc_floor` on EVERY unit,
+    so `max()` selects the EMS floor everywhere the add-on will actually start -
+    which is exactly why the reduction is written here rather than assumed at the
+    call site. "Another rule refuses that config" is a claim about today's rule
+    ordering, not a property of this function, and `validate_startup_config()` is
+    also `sim/inject.py`'s entry point. `unit_caps_indexed()`'s docstring records
+    the same argument, and CFG-04's index desynchronisation is what happened the
+    last time it was left implicit.
+    """
+    if soc_floor is None or pack.bms_floor is None:
+        return None
+    return max(float(soc_floor), float(pack.bms_floor))
+
+
+def pack_permissions(packs, soc_floor) -> list[tuple[str, str | None]]:
+    """SAFETY-32. Per pack: None if it may be spent, else the reason it may not.
+
+    ONE `(name, reason)` pair per pack, in roster order, from the SAME
+    `discharge_permitted()` the site verdict uses - a second transcription of
+    "may this pack be spent" is a second answer to it, which is the argument
+    that made that predicate public in the first place.
+
+    ⚠️ THIS IS THE OBSERVABLE THE MIN() CANNOT PRODUCE. `Controller.pack_floor_soc`
+    reduces the measured SoC to the emptiest pack BEFORE anything is graded, and
+    that reduction is right for the site's one verdict - but it has thrown away
+    which pack it came from and how far that pack was from ITS OWN floor by the
+    time the answer exists. Two packs at 15 % against floors of 10 % and 20 %
+    have opposite answers and are indistinguishable after the `min()`.
+    """
+    return [(p.name, discharge_permitted(p.soc, pack_floor_pct(p, soc_floor)))
+            for p in packs]
+
+
+def binding_soc_floor(packs, soc_floor):
+    """The ONE floor `decide()` may grade `pack_floor_soc` against, at a roster.
+
+    MAXIMUM over the packs' own floors, and it is the conservative reduction that
+    pairs with the MINIMUM `pack_floor_soc` reduction: `min(soc) <= max(floor)`
+    is implied by "some pack is at or below its own floor", so this verdict is
+    never more permissive than grading each pack separately would be. The other
+    direction is not true and is not claimed - a site can be refused here while
+    every pack individually has headroom, which costs a shave and never a pack.
+
+    None when ANY pack's floor is unknown, for `Controller.site_dev_bound()`'s
+    reason and in the same direction: `discharge_permitted()` treats a None floor
+    as no permission, so an unknown floor withholds rather than defaults.
+
+    ⚠️ AT N=1 THIS IS `soc_floor` ITSELF under any config rule 8 accepts, and
+    test_peakguard.py part 12 asserts that over the whole schema range rather
+    than assuming it.
+    """
+    if not packs:
+        return None if soc_floor is None else float(soc_floor)
+    floors = [pack_floor_pct(p, soc_floor) for p in packs]
+    if any(f is None for f in floors):
+        return None
+    return max(floors)
+
+
 def decide(projection, *, batt_w, cap_w, reading, achievable_w, soc, soc_floor,
            max_hold_s=None, frozen: bool = False) -> PeakDecision:
     """The whole guard. Pure: no clock, no I/O, no state carried between calls.

goodwe_controller/app/validate.py

@@ -132,7 +132,7 @@ NOT READY banner already names the problem, (b) does not apply.
      installed base is on a fixed or static tariff. Refusing to start without a
      price feed would lock those sites out of the add-on entirely.
 
-  8. `peak_soc_floor` at or below `bms_soc_floor`.  [(a)]
+  8. `peak_soc_floor` at or below `bms_soc_floor`, ON ANY UNIT.  [(a)]
      SAFETY-24, and the same shape as 1, 4, 5 and 6. The peak guard can COMMAND
      a discharge to hold a billed quarter down (SAFETY-07), and `peak_soc_floor`
      is the EMS-side bound on how far down it may take the pack. The BMS has its
@@ -142,6 +142,12 @@ NOT READY banner already names the problem, (b) does not apply.
      of binding while its status page reports one - rule 5's "a disarmed guard
      that advertises itself as armed", on the guard whose failure mode is a pack
      that is quietly never available when it is wanted.
+     ⚠️ SAFETY-32: `bms_soc_floor` DESCRIBES A BATTERY, so at a roster it is a
+     per-entry key and this rule grades EVERY unit and NAMES the one it refuses.
+     One number for two packs of different models refuses the wrong config and
+     accepts the wrong one - cut-outs of 10 % and 30 % under `peak_soc_floor: 20`
+     used to start. A missing per-entry cut-out is refused here rather than
+     defaulted: a cut-out invented for a pack IS this defect.
 
      ⚠️ `<=`, NOT `<`, and the equality case is the interesting one. At exactly
      equal, the EMS floor and the pack's cut-out act at the same percent, so the
@@ -386,6 +392,49 @@ def unit_caps_indexed(opts: dict) -> list[tuple[int, float]]:
     return caps
 
 
+def unit_bms_floors_indexed(opts: dict) -> list[tuple[int, object, object]]:
+    """SAFETY-32. Each pack's OWN `bms_soc_floor`, carrying its ROSTER INDEX.
+
+    `(roster index, the raw value as configured, the parsed float or None)`, one
+    triple per unit. The raw value travels too because the refusal quotes what
+    the operator actually wrote, and `!r` of a re-read `opts` key is the wrong
+    string the moment the value came off a roster entry.
+
+    ⚠️ THE INDEX IS THE ROSTER'S, NOT THIS LIST'S, AND THAT IS CFG-04'S BUG
+    WRITTEN DOWN. Rules 5 and 6 fed a CAPS-list index into `_unit_label()`,
+    which indexes the ROSTER, so on a roster whose first entry was malformed the
+    refusal named the WRONG INVERTER - an operator sent to the wrong device by
+    the very message that exists to stop that. `unit_caps_indexed()` exists
+    because of it. This function goes one step further and SKIPS NOTHING: every
+    entry produces a triple, including the ones with no usable floor, because a
+    missing cut-out is itself what rule 8 has to refuse BY NAME. There is
+    therefore no second list for an index to desynchronise from.
+
+    ⚠️ AND NOTHING IS INHERITED. At a declared roster the FLAT `bms_soc_floor` is
+    not read at all - CFG-04's rule, and this card's subject: a pack that borrows
+    a sibling's cut-out is graded against a battery it is not. At the flat shape
+    the flat key IS this one pack's cut-out, defaulted from CFG-03's single
+    mirror exactly as `inverter._flat_bms_floor()` defaults it.
+    """
+    entries = roster_entries(opts)
+    if not entries:
+        return [(0, opts.get("bms_soc_floor"),
+                 _number(opts, "bms_soc_floor",
+                         PEAK_OPTION_DEFAULTS["bms_soc_floor"]))]
+    out: list[tuple[int, object, object]] = []
+    for index, entry in enumerate(entries):
+        if not isinstance(entry, dict):
+            # Rule 9(a)/(b) already refuses a non-dict entry by index, and it
+            # runs FIRST. Naming it twice would hand the operator two sentences
+            # about one line of YAML.
+            continue
+        raw = entry.get("bms_soc_floor")
+        out.append((index, raw,
+                    None if raw is None or raw == ""
+                    else _number(entry, "bms_soc_floor", None)))
+    return out
+
+
 def _unit_label(opts: dict, index: int) -> str:
     """"" at a single-inverter config, " (inverter-b)" at a roster.
 
@@ -757,21 +806,48 @@ def validate_startup_config(opts: dict, dev_min=None, dev_max=None) -> list[str]
     # second inverter is added - which is the day nobody is watching the startup
     # log. This is `meter_max_age_s`'s rule read the same way: the failure it
     # prevents is silent.
+    #
+    # ⚠️ AND IT READS THE WEAKEST UNIT'S CAP, NOT THE FLAT `max_w` - SAFETY-32
+    # ROUND 5. This branch used to compare against `max_w = _number(opts,
+    # "max_w", 2000.0)`, the FLAT option, which on a roster config is either
+    # ABSENT (so it compared against a 2000 W DEFAULT describing no unit on the
+    # site) or a leftover from a single-inverter install (so it compared against
+    # a number no unit has). Both directions were live and both were measured:
+    #
+    #   a roster of two 2000 W units beside a leftover `max_w: 5000` and
+    #   `unit_sign_disagree_w: 3000` produced ZERO problems - the site STARTED,
+    #   with a per-inverter watchdog reporting `armed` on the status page and
+    #   incapable of tripping on EITHER unit. That is the identical sentence the
+    #   branch above exists to refuse, reached through the branch beside it;
+    #
+    #   and a roster of two 5000 W units with no flat key was REFUSED at
+    #   `unit_sign_disagree_w: 3000` against a 2000 W default the operator never
+    #   wrote, for a threshold both units can reach.
+    #
+    # `unit_caps()`'s own docstring already said why: there is no such thing as
+    # a site rating on the wire, and this watchdog grades ONE UNIT's standing
+    # command against THAT unit's `supervised` bound. So it takes the same
+    # `weakest` the branch above takes, from the same list, and names the same
+    # unit. At a roster of one `unit_caps()` is `[max_w]` and this is the
+    # identical comparison it always was - which is what keeps the shipped
+    # single-inverter refusal byte-for-byte what it was.
     unit_sign_w = _number(opts, "unit_sign_disagree_w",
                           float(SIGN_OPTION_DEFAULTS["unit_sign_disagree_w"]))
+    unit_where = (_unit_label(opts, min(caps_ix, key=lambda p: p[1])[0])
+                  if caps_ix else "")
     if unit_sign_w is None:
         problems.append(f"unit_sign_disagree_w "
                         f"{opts.get('unit_sign_disagree_w')!r} is not a number")
-    elif max_w is not None and max_w > 0 and unit_sign_w >= max_w:
+    elif weakest is not None and weakest > 0 and unit_sign_w >= weakest:
         problems.append(
-            f"unit_sign_disagree_w is {unit_sign_w:.0f} W but max_w is "
-            f"{max_w:.0f} W, so the SAFETY-30 per-inverter sign-disagreement "
+            f"unit_sign_disagree_w is {unit_sign_w:.0f} W but max_w{unit_where}"
+            f" is {weakest:.0f} W, so the SAFETY-30 per-inverter sign-disagreement "
             "watchdog can never fire: no inverter is ever commanded past max_w, "
             f"and the watchdog needs a command over {unit_sign_w:.0f} W. At two "
             "inverters that is the guard which catches a unit doing the "
             "OPPOSITE of what it was told while its sibling covers for it at "
             "the meter - the case the site-level watchdog is structurally "
-            f"blind to. Lower unit_sign_disagree_w below {max_w:.0f} W "
+            f"blind to. Lower unit_sign_disagree_w below {weakest:.0f} W "
             f"({SIGN_OPTION_DEFAULTS['unit_sign_disagree_w']:.0f} W is the "
             "measured default), or raise max_w.")
 
@@ -871,28 +947,39 @@ def validate_startup_config(opts: dict, dev_min=None, dev_max=None) -> list[str]
     # in-code mirror, pinned to config.yaml by test_peakguard.py, and main.py
     # reads the same one - exactly as maintenance.MAINT_OPTION_DEFAULTS now is
     # for the `maintenance_*` family.
+    #
+    # ⚠️ SAFETY-32 - GRADED ONCE PER UNIT, AND THE REFUSAL NAMES THE UNIT. One
+    # `bms_soc_floor` for two packs compares the EMS floor against whichever
+    # battery happened to be written into the flat key: a site with cut-outs of
+    # 10 % and 30 % and `peak_soc_floor: 20` STARTED, and the guard would then
+    # command a forced discharge that the second pack's BMS - not the operator's
+    # floor - is the thing that stops. That is the disarmed-backstop state this
+    # rule exists to refuse, reached through the rule itself. So the loop is over
+    # units, and `_unit_label()` is fed the ROSTER index the value came off (see
+    # `unit_bms_floors_indexed()`), because CFG-04 has just fixed the version of
+    # this that named the wrong inverter.
     soc_floor = _number(opts, "peak_soc_floor",
                         PEAK_OPTION_DEFAULTS["peak_soc_floor"])
-    bms_floor = _number(opts, "bms_soc_floor",
-                        PEAK_OPTION_DEFAULTS["bms_soc_floor"])
-    if soc_floor is None or bms_floor is None:
-        problems.append(
-            "peak_soc_floor and bms_soc_floor must both be numbers (got "
-            f"{opts.get('peak_soc_floor')!r} / {opts.get('bms_soc_floor')!r})")
-    elif soc_floor <= bms_floor:
-        problems.append(
-            f"peak_soc_floor is {soc_floor:.0f} % but the pack's own cut-out "
-            f"(bms_soc_floor) is {bms_floor:.0f} %, so SAFETY-07's forced "
-            "discharge has no EMS-side bound at all - THE BMS WINS, and it is "
-            "the pack's protection rather than yours. The guard would report a "
-            "SoC floor on its status page while being incapable of ever being "
-            "the thing that stops the discharge, and the symptom of that is a "
-            "battery repeatedly sitting at the BMS limit with no record of why "
-            f"- which looks exactly like the SoC drift the maintenance cycle "
-            f"exists to correct. Raise peak_soc_floor above {bms_floor:.0f} % "
-            f"(the shipped default is "
-            f"{PEAK_OPTION_DEFAULTS['peak_soc_floor']:.0f} %), or correct "
-            "bms_soc_floor if it does not match this pack.")
+    for _ix, _raw, bms_floor in unit_bms_floors_indexed(opts):
+        where = _unit_label(opts, _ix)
+        if soc_floor is None or bms_floor is None:
+            problems.append(
+                f"peak_soc_floor and bms_soc_floor{where} must both be numbers "
+                f"(got {opts.get('peak_soc_floor')!r} / {_raw!r})")
+        elif soc_floor <= bms_floor:
+            problems.append(
+                f"peak_soc_floor is {soc_floor:.0f} % but the pack's own cut-out "
+                f"(bms_soc_floor{where}) is {bms_floor:.0f} %, so SAFETY-07's forced "
+                "discharge has no EMS-side bound at all - THE BMS WINS, and it is "
+                "the pack's protection rather than yours. The guard would report a "
+                "SoC floor on its status page while being incapable of ever being "
+                "the thing that stops the discharge, and the symptom of that is a "
+                "battery repeatedly sitting at the BMS limit with no record of why "
+                f"- which looks exactly like the SoC drift the maintenance cycle "
+                f"exists to correct. Raise peak_soc_floor above {bms_floor:.0f} % "
+                f"(the shipped default is "
+                f"{PEAK_OPTION_DEFAULTS['peak_soc_floor']:.0f} %), or correct "
+                f"bms_soc_floor{where} if it does not match this pack.")
 
     # --- warnings: real, but not worth refusing over -------------------------
     integ = opts.get("integrator_max_w")

goodwe_controller/config.yaml

@@ -56,23 +56,58 @@ options:
   #       soc_entity: sensor.goodwe_a_soc
   #       batt_entity: sensor.goodwe_a_battery_power
   #       max_w: 5000
+  #       bms_soc_floor: 10
   #     - name: inverter-b
   #       setpoint_entity: number.goodwe_b_setpoint_w
   #       soc_entity: sensor.goodwe_b_soc
   #       batt_entity: sensor.goodwe_b_battery_power
-  #       max_w: 3000
+  #       max_w: 4600
+  #       bms_soc_floor: 10
+  #
+  # ⚠️ THE 4600 IS INVERTER B'S DATASHEET FIGURE, NOT A MEASUREMENT AND NOT A
+  # PLACEHOLDER. SPIKE-04a (2026-09-04) identified B as a GoodWe GW5048D-ES,
+  # serial `55048ESU22AW0992`, whose datasheet gives Max. Charging / Discharging
+  # Power as 4600 W; nothing will be connected to its MPPTs, so the battery path
+  # is the ceiling and the 5000 VA AC nameplate is not. The 3000 W this example
+  # used to carry was a guess made before the unit was known. ⚠️ It is STILL not
+  # measured: the datasheet prints 4600 W under BATTERY INPUT DATA, so it may be
+  # DC, and `max_w` is graded against 0x0518 - the inverter's own AC power. If it
+  # is DC the AC ceiling is nearer 4324 W. SAFETY-20's `min(max_w, dev_max)` is
+  # what settles that once the device range is read; see goodwe/NOTES.md §1.1b,
+  # which records both readings and picks neither.
+  #
+  # ⚠️ AND THE `bms_soc_floor: 10` BESIDE IT IS FROM THE SAME PLACE - THE
+  # DATASHEET AND THE SERIAL, NOT A PACK ANYONE HAS READ. No second inverter
+  # exists on this site (SPIKE-04, ≈ 2026-09-12 for B); the cut-out must be read
+  # off the pack that is actually installed (register 0x0560 on the reference
+  # unit) before that pack is commanded. It reads 10 here because pack A reads
+  # 10, which makes this example DEGENERATE ON THE FLOOR AXIS: a site whose two
+  # packs floor at the SAME percent cannot separate `min`, `max`, first or last
+  # over the roster, and every SAFETY-32 fixture that DIFFERS the floors differs
+  # it for exactly that reason. Do not "simplify" those fixtures to match this
+  # example.
   #
   # ⚠️ NOTHING IS INHERITED FROM THE FLAT KEYS BY AN ENTRY THAT OMITS IT, and
   # that is the whole of DEV-02 restated as a config rule. `soc`, `batt` and the
   # rating became per-instance precisely so that no inverter is ever graded
   # against a sibling's numbers; an entry silently inheriting `soc_entity` would
-  # rebuild that defect in YAML. `name`, `setpoint_entity` and `max_w` are
-  # therefore REQUIRED of every entry (the schema below enforces it, and
+  # 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
   # 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".
   #
+  # ⚠️ SAFETY-32: `bms_soc_floor` IS PER ENTRY AND IS REQUIRED, NOT DEFAULTED.
+  # It is the percent THAT pack's own BMS cuts out at, and two batteries of
+  # different models do not share one. A default would be this add-on inventing
+  # a cut-out for a battery it has not been told about, which is the same defect
+  # as inheriting one: the shallower pack gets protected by a floor that belongs
+  # to the deeper pack, and validate.py rule 8 - which refuses a peak_soc_floor
+  # the BMS would win against - would be grading the wrong number. Rule 8 grades
+  # EVERY entry and names the one it refuses. The flat key below is unchanged and
+  # is the single-inverter shape's own cut-out.
+  #
   # ⚠️ AND THE FLAT `setpoint_entity` MUST THEN BE BLANK. Leaving it set while a
   # roster is declared is two config sites aimed at actuators, one of which
   # nothing writes; if it names an entity an entry also names, SAFETY-28's
@@ -355,6 +390,13 @@ options:
   # DoD 90. It is here so validate.py can REFUSE a peak_soc_floor at or below
   # it: such a floor can never bind, the BMS wins, and the status page would
   # report an energy backstop that does not exist.
+  #
+  # ⚠️ SAFETY-32 - THIS KEY DESCRIBES ONE PACK, so it is the SINGLE-INVERTER
+  # shape's number and nothing more. Declare an `inverters:` roster and each
+  # entry states its own `bms_soc_floor`; this one is not read at all and is
+  # not inherited by any entry. Rule 8 then grades every unit separately, which
+  # is the whole of that card: one cut-out for two packs of different models
+  # protects the shallower pack with the deeper pack's number.
   bms_soc_floor: 10
 
   # ⚠️ THE OLD PRICE PATH, AND IT IS NOT DEAD YET. These two entities are the
@@ -500,6 +542,7 @@ schema:
     - name: str
       setpoint_entity: str
       max_w: int(100,5000)
+      bms_soc_floor: int(0,50)
       soc_entity: str?
       batt_entity: str?
       batt_invert: bool?

goodwe_controller/test_inverter.py

@@ -192,10 +192,27 @@ class Hass:
 
 A_ENT = {"setpoint_entity": "number.sp_a", "soc_entity": "sensor.soc_a",
          "batt_entity": "sensor.batt_a"}
-# ⚠️ A HYPOTHESIS, NOT A MEASUREMENT. Inverter B does not exist; 3000 W is
-# chosen only because it DIFFERS from A's 5000 W, which is what lets a check
-# tell B's number from A's. SPIKE-04 measures the real one.
+# ⚠️ SPIKE-04a (2026-09-04) ESTABLISHED B'S REAL RATING FROM ITS DATASHEET:
+# a GoodWe GW5048D-ES, serial `55048ESU22AW0992`, 4600 W on the battery path
+# (goodwe/NOTES.md §1.1b). THIS FIXTURE DELIBERATELY DOES NOT USE IT. 3000 W is
+# kept because the only property these checks consume is that B's number is
+# UNMISTAKABLY not A's, and the real pair is 5000/4600 - a 400 W gap, narrower
+# than `slew_w` and inside the range where an off-by-one-unit bug and ordinary
+# control arithmetic produce indistinguishable numbers. Collapsing the fixture
+# onto the real values would cost these checks their separating power to buy
+# realism they do not use. So: ILLUSTRATIVE, NOT B'S RATING, and not a
+# placeholder for it either - the placeholder era ended on 2026-09-04.
 B_RATING_HYPOTHESIS = 3000.0
+# SAFETY-32. Each pack's OWN BMS cut-out percent, now a REQUIRED roster key.
+# ⚠️ 10 IS MEASURED (register 0x0560 on the reference GW5000S-BP and the shipped
+# `bms_soc_floor` default); 15 IS SIMULATED - there is no second pack. They
+# DIFFER on purpose: a fixture whose two per-unit numbers are equal cannot show
+# a check that read the wrong unit's, which is MUTATION.md habit 1 and the defect
+# that has now bitten four consecutive cards. Both sit below the shipped
+# `peak_soc_floor` of 20, so rule 8 accepts this roster.
+A_BMS_FLOOR = 10
+B_BMS_FLOOR_SIM = 15
+
 A_RATING = 5000.0
 
 BASE_OPTS = dict(A_ENT, meter_source="off", meter_entity="sensor.grid",
@@ -1411,13 +1428,16 @@ _TWO_OPTS.pop("batt_entity")
 _TWO_OPTS["inverters"] = [
     dict(name="inverter-a", setpoint_entity="number.sp_a",
          soc_entity="sensor.soc_a", batt_entity="sensor.batt_a",
-         max_w=A_RATING),
+         max_w=A_RATING, bms_soc_floor=A_BMS_FLOOR),
     # ⚠️ 3000 W IS A HYPOTHESIS AND IS MARKED AS ONE WHEREVER IT APPEARS. It is
     # here because it DIFFERS from A's 5000 W, which is the only property any
     # check below uses. SPIKE-04 measures the real device.
+    # ⚠️ AND SO IS ITS 15 % CUT-OUT (SAFETY-32). There is no second pack to read
+    # register 0x0560 off; the value is SIMULATED, and it differs from A's 10 %
+    # for MUTATION.md habit 1's reason and no other.
     dict(name="inverter-b", setpoint_entity="number.sp_b",
          soc_entity="sensor.soc_b", batt_entity="sensor.batt_b",
-         max_w=B_RATING_HYPOTHESIS),
+         max_w=B_RATING_HYPOTHESIS, bms_soc_floor=B_BMS_FLOOR_SIM),
 ]
 _c9, _hass9 = built(_TWO_OPTS)
 print(f"    the roster built from `inverters:` -> {[repr(i) for i in _c9.inverters]}")
@@ -1493,14 +1513,19 @@ _decl9 = dict(ln.strip().lstrip("- ").split(": ", 1)
               for ln in _entry9.splitlines()[1:] if ": " in ln)
 print(f"    the shipped per-entry schema: {_decl9}")
 check("...and the schema half declares it as a LIST OF OBJECTS whose `name`, "
-      "`setpoint_entity` and `max_w` are REQUIRED - no trailing `?` - so the "
-      "Supervisor refuses a half-written entry before the add-on sees it, and "
-      "an entry can never fall back on a sibling's rating because there is no "
-      "entry without one",
-      set(_decl9) == {"name", "setpoint_entity", "max_w", "soc_entity",
-                      "batt_entity", "batt_invert"}
+      "`setpoint_entity`, `max_w` and `bms_soc_floor` are REQUIRED - no "
+      "trailing `?` - so the Supervisor refuses a half-written entry before the "
+      "add-on sees it, and an entry can never fall back on a sibling's rating "
+      "or on a sibling's BMS cut-out because there is no entry without one. "
+      "⚠️ SAFETY-32 ADDED THE FOURTH ONE AS REQUIRED RATHER THAN AS "
+      "`int(0,50)?`, and the difference is the whole of that card: an optional "
+      "per-pack cut-out is a DEFAULTED one, and a default is one number for "
+      "two batteries - the shallower pack protected by the deeper pack's BMS",
+      set(_decl9) == {"name", "setpoint_entity", "max_w", "bms_soc_floor",
+                      "soc_entity", "batt_entity", "batt_invert"}
       and not any(_decl9[k].endswith("?")
-                  for k in ("name", "setpoint_entity", "max_w"))
+                  for k in ("name", "setpoint_entity", "max_w",
+                            "bms_soc_floor"))
       and all(_decl9[k].endswith("?")
               for k in ("soc_entity", "batt_entity", "batt_invert")))
 
@@ -1582,9 +1607,11 @@ check("...and two inverters on two DIFFERENT entities are accepted, because "
       "that is the configuration this card exists for and a validator that "
       "fires on the legitimate case gets switched off",
       validate_startup_config(_opts(setpoint_entity="", inverters=[
-          dict(name="inverter-a", setpoint_entity="number.sp_a", max_w=A_RATING),
+          dict(name="inverter-a", setpoint_entity="number.sp_a", max_w=A_RATING,
+               bms_soc_floor=A_BMS_FLOOR),
           dict(name="inverter-b", setpoint_entity="number.sp_b",
-               max_w=B_RATING_HYPOTHESIS)])) == [])
+               max_w=B_RATING_HYPOTHESIS,
+               bms_soc_floor=B_BMS_FLOOR_SIM)])) == [])
 
 # --- the rest of rule 9 -------------------------------------------------------
 _p_flat = validate_startup_config(_opts(inverters=[

goodwe_controller/test_maintenance.py

@@ -1059,9 +1059,16 @@ class Pub:
         pass
 
 
-# ⚠️ 3000 W FOR PACK B IS A HYPOTHESIS AND IS MARKED AS ONE EVERYWHERE IT
-# APPEARS. Inverter B does not physically exist; the number is here only because
-# it DIFFERS from pack A's 5000 W, which is the only property these checks use.
+# ⚠️ SPIKE-04a (2026-09-04) ESTABLISHED B'S REAL RATING FROM ITS DATASHEET:
+# a GoodWe GW5048D-ES, serial `55048ESU22AW0992`, 4600 W on the battery path
+# (goodwe/NOTES.md §1.1b). THIS FIXTURE DELIBERATELY DOES NOT USE IT. 3000 W is
+# kept because the only property these checks consume is that B's number is
+# UNMISTAKABLY not A's, and the real pair is 5000/4600 - a 400 W gap, narrower
+# than `slew_w` and inside the range where an off-by-one-unit bug and ordinary
+# control arithmetic produce indistinguishable numbers. Collapsing the fixture
+# onto the real values would cost these checks their separating power to buy
+# realism they do not use. So: ILLUSTRATIVE, NOT B'S RATING, and not a
+# placeholder for it either - the placeholder era ended on 2026-09-04.
 B_RATING_HYPOTHESIS = 3000.0
 A_RATING = 5000.0
 FLAT_OPTS = dict(setpoint_entity="number.sp_a", soc_entity="sensor.soc_a",

goodwe_controller/test_validate.py

@@ -204,12 +204,17 @@ check("...and the refusal names the actuator and every writer aimed at it, so "
 _PER_INVERTER_OK = {k: v for k, v in base().items() if k != "setpoint_entity"}
 _PER_INVERTER_OK["inverters"] = [
     {"name": "inverter-a", "setpoint_entity": "number.goodwe_setpoint",
-     "max_w": 2000},
+     "max_w": 2000, "bms_soc_floor": 10},
     # ⚠️ INVERTER B DOES NOT EXIST. 2000 W here is the SHIPPED default repeated,
     # not a rating measured off a second device - SPIKE-04 measures that when
     # there is one to measure. Nothing in this file depends on the number.
+    # ⚠️ SAFETY-32 made `bms_soc_floor` a REQUIRED per-entry key, and the two
+    # values here DIFFER (10 / 15) rather than being copied. 15 % is SIMULATED -
+    # there is no second pack to read a cut-out off - and the reason it is not
+    # simply 10 is MUTATION.md habit 1: a fixture whose two per-unit numbers are
+    # equal cannot show a check reading the wrong unit's.
     {"name": "inverter-b", "setpoint_entity": "number.goodwe_setpoint_b",
-     "max_w": 2000}]
+     "max_w": 2000, "bms_soc_floor": 15}]
 check("two inverters with their own entities are ACCEPTED - one writer each, "
       "no shared actuator, and that is CFG-04's whole purpose",
       validate_startup_config(_PER_INVERTER_OK, -5000, 5000) == [])
@@ -828,6 +833,339 @@ check("...and MaintConfig's dataclass defaults carry no numeric literal either "
       not re.search(r"^\s*(charge_w|discharge_w):\s*float\s*=\s*-?\d",
                     _srcs["maintenance.py"], re.M))
 
+# --------------------------------------------------------------------------- #
+print("SPIKE-04a: inverter B's documented rating, and the provenance beside it")
+# ⚠️ WHY A DOCUMENTATION CARD LEFT A CHECK BEHIND. Inverter B's rating was
+# written down in THREE places - config.yaml's commented roster example,
+# DOCS.md's, and tools/supervisor_shape_probe.py's "a blob an operator would
+# POST" - as 3000 W, a figure nobody had measured, read off a datasheet, or
+# sourced at all. It was wrong: SPIKE-04a (2026-09-04) identified inverter B
+# from the owner's model number and serial as a GoodWe GW5048D-ES rated 4600 W
+# on the battery path. Three transcriptions of one number drifting away from
+# the truth together is this repo's recurring defect in its plainest form, and
+# correcting them once WITHOUT PINNING THEM buys nothing: the next editor
+# touches one of the three and the other two stay wrong, silently.
+#
+# ⚠️ AND THE PROVENANCE IS GRADED, NOT ONLY THE VALUE, WHICH IS THE HALF THAT
+# MATTERS. 4600 W IS FROM A DATASHEET AND IS NOT A MEASUREMENT. The datasheet
+# prints it under BATTERY INPUT DATA, so it is probably DC, while `max_w` is
+# graded against 0x0518 - the inverter's own AC power - which would put the AC
+# ceiling nearer 4324 W. An editor who tidies that caveat away leaves a paper
+# number reading as an observation of hardware that does not exist yet, and
+# THAT is the failure this card exists to prevent. So the caveat is what these
+# checks reach for; a check that graded 4600 alone would watch the value and
+# miss the lie.
+#
+# ⚠️ WHAT THIS DELIBERATELY DOES NOT GRADE: the test fixtures. Several files
+# build a second inverter at 3000 W on purpose, because the property those
+# checks consume is that B's rating is UNMISTAKABLY not A's, and the real pair
+# (5000/4600) is a 400 W gap - narrower than `slew_w`. Those are illustrative,
+# they say so at the line, and they are not statements of B's rating. The three
+# sites below are the ones that ARE such statements.
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_docs_txt = open(os.path.join(_HERE, "DOCS.md"), encoding="utf-8").read()
+_probe_txt = open(os.path.join(_HERE, "tools", "supervisor_shape_probe.py"),
+                  encoding="utf-8").read()
+
+# One regex per site, each anchored on something only THAT site has, so a match
+# cannot silently wander into a neighbouring blob. The probe's anchor is the
+# operator blob's real entity name: its section D refusal entries use
+# `number.b` and one of them carries a deliberate 9999, so an anchor loose
+# enough to reach them would grade the wrong dict and still look green.
+_b_rating = {
+    "config.yaml": re.search(
+        r"#\s+- name: inverter-b\b(?:[^\n]*\n)*?\s*#\s+max_w:\s*(\d+)", _txt),
+    "DOCS.md": re.search(
+        r"^  - name: inverter-b\b(?:[^\n]*\n)*?^    max_w:\s*(\d+)",
+        _docs_txt, re.M),
+    "supervisor_shape_probe.py": re.search(
+        r'"name": "inverter-b",\s*"setpoint_entity": "number\.goodwe_b_setpoint_w"'
+        r'(?:[^}]*?)"max_w":\s*(\d+)', _probe_txt),
+}
+check(f"all three documented rosters were FOUND "
+      f"{ {k: bool(v) for k, v in _b_rating.items()} } - a regex that matches "
+      "nothing is a green check that read nothing",
+      all(_b_rating.values()))
+# ⚠️ THE `len(...) == 3` IS NOT DECORATION. Without it a regex that stopped
+# matching would shrink this dict, and "all the values agree" would go GREEN on
+# the two sites that were still read - a check whose data no longer reaches the
+# failure it names, which is the exact fault this whole section is about.
+_b_vals = {k: int(m.group(1)) for k, m in _b_rating.items() if m}
+check(f"...and all three state the SAME rating for inverter B {_b_vals}",
+      len(_b_vals) == 3 and len(set(_b_vals.values())) == 1)
+check(f"...and it is 4600 W - the GW5048D-ES datasheet figure, not the 3000 W "
+      f"hypothesis that predated the unit being identified {_b_vals}",
+      len(_b_vals) == 3 and set(_b_vals.values()) == {4600})
+
+# The provenance triple. Each site must still say WHERE 4600 came from, that it
+# is graded against an AC register, and what the DC-vs-AC ambiguity does to it -
+# the last carried by the 4324 W figure, which is the one marker that cannot
+# survive a careless "it's 4600 now, done" rewrite.
+#
+# ⚠️ SEARCHED IN A WINDOW AROUND THE ROSTER, NOT OVER THE WHOLE FILE, AND THE
+# FIRST VERSION OF THIS CHECK DID THE LATTER. `0x0518` already appeared once in
+# config.yaml and once in DOCS.md before this card, for unrelated reasons - so a
+# whole-file `"0x0518" in src` was GREEN on those two files no matter what
+# happened next to inverter B's rating. That is a check whose data cannot reach
+# the failure it names, in the same file that exists to complain about them.
+# The window is the text either side of the roster match, so deleting the caveat
+# beside the number goes red even where the same word survives elsewhere.
+_sites = {"config.yaml": _txt, "DOCS.md": _docs_txt,
+          "supervisor_shape_probe.py": _probe_txt}
+_MARKERS = ("datasheet", "0x0518", "4324")
+_prov = {}
+for _name, _src in _sites.items():
+    _m = _b_rating[_name]
+    _win = _src[max(0, _m.start() - 2500):_m.end() + 2500].lower() if _m else ""
+    _prov[_name] = {k: k in _win for k in _MARKERS}
+for _name, _got in sorted(_prov.items()):
+    check(f"{_name} still carries B's provenance WITHIN 2500 chars of the "
+          f"roster - the datasheet it came from, the 0x0518 it is graded "
+          f"against, and the 4324 W the DC reading would make it {_got}",
+          all(_got.values()))
+
+
+# --------------------------------------------------------------------------- #
+print("rules 5, 5b and 6 on a ROSTER SET - the smallest cap at EVERY position")
+# ⚠️ SAFETY-32 ROUND 5, AND THE REASON THIS SECTION EXISTS AT ALL. PR #48 was
+# rejected on FOUR MUTATIONS THAT SURVIVED A 19/19 GREEN SUITE, all of them in
+# the three lines above:
+#
+#   validate.py:779  min(caps)   -> min(caps[:1])                  +4 B  GREEN
+#   validate.py:779  min(caps)   -> min(caps[-1:])                 +5 B  GREEN
+#   validate.py:778  caps = [cap for _, cap in caps_ix[:1]]        +4 B  GREEN
+#   validate.py:893  min(caps_ix[-1:], key=lambda p: p[1])         +5 B  GREEN
+#
+# NONE of them is an equivalent mutant: each one deletes a safety refusal.
+# `max_w: 5000` on inverter-a beside `2000` on inverter-b with
+# `sign_disagree_w: 3000` is refused by the shipped validator with "the
+# SAFETY-02 sign-disagreement watchdog can never fire" and ACCEPTED by every one
+# of the four - the site starts, with a watchdog that reports `armed` on the
+# status page and cannot trip on pack B. That is rule 5's own failure mode
+# reached THROUGH rule 5.
+#
+# WHY THE OLD FIXTURE COULD NOT SEE IT, which is the whole lesson and is now
+# MUTATION.md habit 10: the fixture was ONE roster, `[5000, 2000]`. On that
+# roster `min` and `last` and `[-1:]` and `[:2]` all answer 2000. A fixture of N
+# members cannot separate two reductions that agree on N members, and adding a
+# member moves the hole instead of closing it.
+#
+# SO THE FIXTURE IS A SET, NOT A ROSTER: the smallest cap at EVERY POSITION of
+# rosters of width 2, 3, 4 and 5. `[:1]` needs width 2 to be caught, `[:2]`
+# needs 3, `[:3]` needs 4 - the sweep is what terminates the regress that a
+# single fixture cannot. And the FAMILY TABLE below is COMPUTED AND PRINTED, so
+# a member no fixture kills shows up as a NAMED SURVIVOR rather than as an
+# absence from a list nobody re-derived.
+#
+# ⚠️ THE DIFFERING CAPS ARE A FIXTURE PROPERTY AND MUST STAY ONE. In production
+# both packs are expected to floor at 10 % and SPIKE-04a puts inverter B at
+# 4600 W against A's 5000 W - a 400 W gap, narrower than slew_w. A fixture built
+# on the real pair would be degenerate on exactly the axis these checks measure.
+# ⚠️ AND INVERTER B DOES NOT PHYSICALLY EXIST (SPIKE-04, ~2026-09-12). Nothing
+# in this section is measured off a second unit; the rosters are simulated and
+# are labelled so.
+_BIG, _SMALL = 5000.0, 2000.0
+_RATE = 3000.0                     # strictly between them, which is the point
+
+
+def _roster_n(caps, **over):
+    """A roster of len(caps) units, unit-0..unit-N, each with its own cap."""
+    o = base(**over)
+    for k in ("setpoint_entity", "soc_entity", "batt_entity", "max_w"):
+        o.pop(k, None)
+    o["inverters"] = [
+        dict(name=f"unit-{i}", setpoint_entity=f"number.sp{i}",
+             soc_entity=f"sensor.soc{i}", batt_entity=f"sensor.batt{i}",
+             max_w=c, bms_soc_floor=10)
+        for i, c in enumerate(caps)]
+    o.update(over)
+    return o
+
+
+# The three rules that reduce over `unit_caps_indexed()`, each as
+# (option name, the token its refusal is recognised by).
+_CAP_RULES = (
+    ("sign_disagree_w", "SAFETY-02 sign-disagreement"),
+    ("unit_sign_disagree_w", "SAFETY-30 per-inverter sign-disagreement"),
+    ("maintenance_charge_w", "maintenance charge in a cheap window"),
+)
+_QUIET = {"sign_disagree_w": 300.0, "unit_sign_disagree_w": 300.0,
+          "maintenance_charge_w": 1000.0, "maintenance_discharge_w": 1000.0}
+
+# THE SET: width x position of the one small cap.
+_SET = []
+for _n in (2, 3, 4, 5):
+    for _pos in range(_n):
+        _caps = [_BIG] * _n
+        _caps[_pos] = _SMALL
+        _SET.append((_n, _pos, tuple(_caps)))
+
+# habit 1: the PRECONDITION as its own check. If a later edit makes the caps
+# equal, this goes red rather than the claims below going quietly vacuous.
+check("PRECONDITION: every fixture in the set has a UNIQUE smallest cap, that "
+      "cap is at the stated position, and the rate under test sits STRICTLY "
+      "between it and the others - two equal caps could not tell `min` from "
+      "`first` from `last` and the whole set would be measuring nothing",
+      len(_SET) == 14
+      and all(c[p] == _SMALL and c.count(_SMALL) == 1 and _SMALL < _RATE < _BIG
+              for _n2, p, c in _SET)
+      and {p for _n2, p, _c in _SET} == {0, 1, 2, 3, 4})
+
+
+def _verdict(opts, token):
+    """(refused?, the unit the message NAMES, the cap it QUOTES)."""
+    ps = [p for p in validate_startup_config(opts, -5000, 5000) if token in p]
+    if not ps:
+        return (False, None, None)
+    m = re.search(r"max_w \(([^)]+)\) is (\d+) W", ps[0])
+    return (True, m.group(1) if m else None, float(m.group(2)) if m else None)
+
+
+# --- the shipped answer, on every member of the set -------------------------
+_rows = []
+for _opt, _token in _CAP_RULES:
+    for _n, _pos, _caps in _SET:
+        _o = _roster_n(list(_caps), **dict(_QUIET, **{_opt: _RATE}))
+        _rows.append((_opt, _n, _pos, _caps, _verdict(_o, _token)))
+print(f"    {len(_CAP_RULES)} rules x {len(_SET)} rosters = {len(_rows)} runs "
+      f"of the REAL validator (rate {_RATE:.0f} W, caps {_SMALL:.0f}/"
+      f"{_BIG:.0f} W, simulated rosters - inverter B does not exist):")
+for _opt in sorted({r[0] for r in _rows}):
+    _got = [(r[1], r[2], r[4]) for r in _rows if r[0] == _opt]
+    print(f"      {_opt:<22} " + " ".join(
+        f"n{n}p{p}:{'REFUSE ' + str(u) if ok else 'starts'}"
+        for n, p, (ok, u, _c) in _got))
+
+check("⚠️ EVERY ONE OF THE THREE CAP RULES REFUSES ON EVERY MEMBER OF THE SET, "
+      "and NAMES THE UNIT THE NUMBER CAME OFF - at width 2, 3, 4 and 5, with "
+      "the small cap at every position in turn. A reduction that answered "
+      "`first`, `last`, `[:1]`, `[-1:]`, `[:2]` or `[:-1]` instead of `min` "
+      "misses at least one member of this set, which is what four hand-run "
+      "mutations against a 19/19 green suite proved the single `[5000, 2000]` "
+      "fixture could not do",
+      all(ok and unit == f"unit-{p}" and cap == _SMALL
+          for _o2, _n2, p, _c2, (ok, unit, cap) in _rows))
+
+check("...and it is a COMPARISON, not a blanket refusal of rosters: the same "
+      "three rates against a roster whose caps can ALL take them start "
+      "cleanly, at every width. Without this the line above is satisfied by a "
+      "validator that refuses everything (habit 2 in the negative direction)",
+      all(_verdict(_roster_n([_BIG] * n, **dict(_QUIET, **{opt: _RATE})),
+                   tok) == (False, None, None)
+          for opt, tok in _CAP_RULES for n in (1, 2, 3, 4, 5)))
+
+# --- the POSITIONAL-SLICE FAMILY TABLE, computed and printed ----------------
+# ⚠️ COMPUTED, NOT LISTED. Each candidate is applied to the SAME caps the
+# validator saw, and its (unit, cap) answer is compared against what the shipped
+# validator actually said on that roster. A candidate that agrees everywhere is
+# a reduction this fixture set CANNOT distinguish from the shipped one, and it
+# is printed as a SURVIVOR rather than left out of a table nobody re-derived.
+def _pick(caps, fn):
+    ix = list(enumerate(caps))
+    try:
+        i, c = fn(ix)
+    except (ValueError, IndexError):
+        return None
+    return (f"unit-{i}", c)
+
+
+_FAMILY = {
+    "min (SHIPPED)":  lambda ix: min(ix, key=lambda p: p[1]),
+    "max":            lambda ix: max(ix, key=lambda p: p[1]),
+    "first":          lambda ix: ix[0],
+    "last":           lambda ix: ix[-1],
+    "min(caps[:1])":  lambda ix: min(ix[:1], key=lambda p: p[1]),
+    "min(caps[-1:])": lambda ix: min(ix[-1:], key=lambda p: p[1]),
+    "min(caps[:2])":  lambda ix: min(ix[:2], key=lambda p: p[1]),
+    "min(caps[:3])":  lambda ix: min(ix[:3], key=lambda p: p[1]),
+    "min(caps[1:])":  lambda ix: min(ix[1:], key=lambda p: p[1]),
+    "min(caps[:-1])": lambda ix: min(ix[:-1], key=lambda p: p[1]),
+    "min(caps[::2])": lambda ix: min(ix[::2], key=lambda p: p[1]),
+    "mean":           lambda ix: (0, sum(c for _i, c in ix) / len(ix)),
+}
+_survivors = []
+print("    the family table - each candidate against what the SHIPPED "
+      "validator answered on the same roster:")
+for _name, _fn in _FAMILY.items():
+    _misses = []
+    for _opt, _n, _pos, _caps, (_ok, _unit, _cap) in _rows:
+        _pred = _pick(list(_caps), _fn)
+        _pred_refuses = _pred is not None and _pred[1] > 0 and _RATE >= _pred[1]
+        if _opt == "maintenance_charge_w":
+            _pred_refuses = (_pred is not None and _pred[1] > 0
+                             and _RATE > _pred[1])
+        _said = ((True, _pred[0], _pred[1]) if _pred_refuses
+                 else (False, None, None))
+        if _said != (_ok, _unit, _cap):
+            _misses.append(f"{_opt[:4]}/n{_n}p{_pos}")
+    if not _misses and _name != "min (SHIPPED)":
+        _survivors.append(_name)
+    print(f"      {_name:<16} {'AGREES EVERYWHERE (survivor)' if not _misses else 'differs on ' + str(len(_misses)) + ' run(s), first: ' + _misses[0]}")
+check("⚠️ AND THE FAMILY TABLE HAS NO SURVIVOR BUT THE SHIPPED REDUCTION. "
+      "Eleven candidates - max, first, last, the mean, and every positional "
+      "slice this card has actually been defeated by - are each computed "
+      "against what the real validator answered on the same roster, and every "
+      "one of them differs somewhere in the set. This is the check that would "
+      "have taken PR #48 red four rounds ago: a member no fixture kills is "
+      "PRINTED AS A NAMED SURVIVOR here instead of being absent from a list "
+      f"nobody re-derived. survivors: {_survivors}",
+      _survivors == [])
+
+# --- the ROSTER OF ONE, where every one of them is the same thing -----------
+_at_one = {n: _pick([_SMALL], f) for n, f in _FAMILY.items()}
+print(f"    at a ROSTER OF ONE the twelve candidates answer: "
+      f"{sorted({str(v) for v in _at_one.values()})}")
+check("...and at a ROSTER OF ONE every candidate that still has a member to "
+      "reduce answers THE SAME THING - which is exactly why no "
+      "single-inverter fixture in this repository could ever have caught any "
+      "of this, and why the shipped single-inverter refusals are what they "
+      "always were. The only two that do NOT coincide are `caps[1:]` and "
+      "`caps[:-1]`, which EMPTY the list and would raise: at N=1 they are "
+      "crashes rather than silent wrong answers, so they are not survivors "
+      "there either",
+      {v for v in _at_one.values() if v is not None} == {("unit-0", _SMALL)}
+      and {n for n, v in _at_one.items() if v is None}
+      == {"min(caps[1:])", "min(caps[:-1])"}
+      and _verdict(_roster_n([_SMALL], **dict(_QUIET, sign_disagree_w=_RATE)),
+                   "SAFETY-02 sign-disagreement")[0])
+
+# --- rule 5's SIBLING BRANCH, which was reading the FLAT max_w --------------
+# ⚠️ FOUND BY READING THE THREE BRANCHES SIDE BY SIDE, NOT BY THE STRUCTURAL
+# PIN - and said that way on purpose, because it is the shape of what the pin
+# cannot see. `unit_sign_disagree_w` is SAFETY-30's, not this card's. It was
+# graded against `_number(opts, "max_w", 2000.0)`, the FLAT option, three lines
+# under a branch that had already stopped doing that. Both directions were
+# measured before the fix and both are asserted here.
+_leftover = _roster_n([_SMALL, _SMALL],
+                      **dict(_QUIET, unit_sign_disagree_w=_RATE))
+_leftover["max_w"] = _BIG          # what a single-inverter install leaves behind
+_lv = _verdict(_leftover, "SAFETY-30 per-inverter sign-disagreement")
+print(f"    leftover flat max_w {_BIG:.0f} beside a roster of two "
+      f"{_SMALL:.0f} W units, unit_sign_disagree_w {_RATE:.0f} -> {_lv}")
+check("⚠️ A LEFTOVER FLAT `max_w` NO LONGER DISARMS SAFETY-30's PER-UNIT "
+      "WATCHDOG SILENTLY. Two 2000 W units beside a `max_w: 5000` left over "
+      "from a single-inverter install and `unit_sign_disagree_w: 3000` used to "
+      "produce ZERO problems - the site started, the status page said `armed`, "
+      "and the watchdog could not trip on EITHER unit. It is refused now, "
+      "against the weakest unit's own cap, and the message names that unit",
+      _lv == (True, "unit-0", _SMALL))
+check("...and the over-refusal in the OTHER direction is gone too: a roster of "
+      "two 5000 W units with NO flat `max_w` was refused at 3000 W against a "
+      "2000 W DEFAULT the operator never wrote, for a threshold both units can "
+      "reach. It starts",
+      _verdict(_roster_n([_BIG, _BIG],
+                         **dict(_QUIET, unit_sign_disagree_w=_RATE)),
+               "SAFETY-30 per-inverter sign-disagreement")
+      == (False, None, None))
+check("...and the flat single-inverter config it always refused is refused "
+      "IDENTICALLY - `unit_caps()` at a roster of one is `[max_w]`, so this is "
+      "the same comparison, the same boundary and the same sentence",
+      why(validate_startup_config(base(max_w=2000, unit_sign_disagree_w=2000),
+                                  -5000, 5000), "unit_sign_disagree_w")
+      and validate_startup_config(base(max_w=2000, unit_sign_disagree_w=1999),
+                                  -5000, 5000) == [])
+
+
 # --------------------------------------------------------------------------- #
 print()
 if fails:

goodwe_controller/test_watchdog.py

@@ -798,9 +798,18 @@ print("   circulation the allocator NEVER COMMANDED")
 
 from app.inverter import Inverter  # noqa: E402
 
-# ⚠️ INVERTER B DOES NOT PHYSICALLY EXIST - it is ~10 days out and SPIKE-04
-# measures it. Its rating here is a HYPOTHESIS, named as one, exactly as
-# test_peakguard.py's helper names its own.
+# ⚠️ INVERTER B DOES NOT PHYSICALLY EXIST - it is ~8 days out (2026-09-04) and
+# the bench half of SPIKE-04 measures it.
+# ⚠️ SPIKE-04a (2026-09-04) ESTABLISHED B'S REAL RATING FROM ITS DATASHEET:
+# a GoodWe GW5048D-ES, serial `55048ESU22AW0992`, 4600 W on the battery path
+# (goodwe/NOTES.md §1.1b). THIS FIXTURE DELIBERATELY DOES NOT USE IT. 3000 W is
+# kept because the only property these checks consume is that B's number is
+# UNMISTAKABLY not A's, and the real pair is 5000/4600 - a 400 W gap, narrower
+# than `slew_w` and inside the range where an off-by-one-unit bug and ordinary
+# control arithmetic produce indistinguishable numbers. Collapsing the fixture
+# onto the real values would cost these checks their separating power to buy
+# realism they do not use. So: ILLUSTRATIVE, NOT B'S RATING, and not a
+# placeholder for it either - the placeholder era ended on 2026-09-04.
 B_RATING_HYPOTHESIS = 3000.0
 
 
@@ -1809,6 +1818,181 @@ check("...and no `sign_site` claim can be filed at a roster of one, so the "
       "arbitration is byte-identical to what shipped",
       "sign_site" not in _c1s.reason)
 
+
+print()
+print("8. SAFETY-32 ROUND 4's ENUMERATION: the two `any(...)` reductions over")
+print("   the roster whose only evidence is a latched NON-FIRST unit")
+# ⚠️ THIS SECTION IS NOT SAFETY-32's SUBJECT, AND IT IS HERE BECAUSE OF IT.
+# SAFETY-32 was rejected three times for the same shape one step over: a
+# reduction over roster length whose fixture could not separate it from a slice
+# of the roster. Round 4 therefore ENUMERATED every such reduction in
+# `Controller` - min, max, sum, any, all, sorted, [0], [-1] over
+# `self.inverters` / `self.packs` - and mutated each to `[:1]` to find out which
+# were GRADED. Two survived a green 19-file suite, both `any(i.sign_wd.tripped
+# for i in self.inverters)`, both SAFETY-30's, and this block is what closes
+# them. No shipped behaviour changes; the reductions were already right.
+#
+#   main.py `cycle()`, the stale-input hold  -  +4 bytes, 19/19 GREEN
+#   main.py `publish()`, the status vocabulary -  +4 bytes, 19/19 GREEN
+#
+# ⚠️ WHY THE SUITE COULD NOT SEE THEM, and it is the same sentence every time:
+# the only fixture that reached either was a roster of ONE, where
+# `self.inverters[:1]` IS `self.inverters`. Part 3 above builds a two-inverter
+# roster in which ONLY inverter B is latched - the exact data both reductions
+# needed - and neither of them was read on it. A fixture of N units cannot
+# separate reductions that agree on N units, one card over.
+#
+# ⚠️ AND BOTH ORDERS ARE RUN, for 12g's reason: a single "only B is latched"
+# fixture kills `[:1]` and leaves `[-1:]` - grade the roster by its LAST unit -
+# answering identically. The pair is what leaves no single-position slice.
+
+
+async def _latched_then_input_gap(reversed_idx):
+    """Latch ONE unit's sign watchdog, then take a SIBLING's reading away.
+
+    ⚠️ A REAL LATCH FROM A REAL EPISODE, not `sign_wd.tripped = True`: the same
+    `_SignHass` plant and the same `_drive()` part 3 uses, so the detector
+    reaches its verdict through the shipped path. Then one pack's SoC goes
+    missing for LESS than `stale_input_s`, which is the state the hold exists
+    for - a single missed poll must not become a fault.
+
+    THE FAULT THIS GRADES: a LATCHED unit must take the whole roster past that
+    hold, because the unit's `failsafe` SET is the thing parking it. Return
+    early and the unit's last share stays standing for the heartbeat to
+    re-emit - main.py's own comment: "the trip would stop acting the moment a
+    poll was missed". A reduction that looked at one roster POSITION would do
+    exactly that whenever the latched unit was not the position it looked at.
+    """
+    hass = _SignHass(load_w=2000.0, reversed_units={reversed_idx})
+    c = _sign_site(hass)
+    await _drive(c)
+    sibling = c.inverters[1 - reversed_idx]
+    sibling.soc = None
+    c.inputs_bad_since = datetime.now(timezone.utc)
+    await c.cycle()
+    return c
+
+
+_gap_b = asyncio.run(_latched_then_input_gap(1))
+_gap_a = asyncio.run(_latched_then_input_gap(0))
+for _tag, _c, _i in (("B latched", _gap_b, 1), ("A latched", _gap_a, 0)):
+    _pl = [p for p in (_c.allocation.plans if _c.allocation else ())
+           if p.unit == _c.inverters[_i].name]
+    print(f"       {_tag}, sibling's SoC missing 0 s: inputs_ok="
+          f"{_c.inputs_ok}, reason={_c.reason!r}, latched unit target="
+          f"{_c.inverters[_i].target}, why={_pl[0].why if _pl else '(no plan)'}")
+check("PRECONDITION (habit 1): on BOTH runs the site really is in the state "
+      "the hold is for - one pack's reading is missing, `inputs_ok` is False, "
+      "the gap is younger than `stale_input_s`, and the SITE latch is NOT "
+      "tripped, so the only thing that can carry the roster past the hold is "
+      "the per-unit `any()`. And exactly ONE unit is latched on each run, at "
+      "the OTHER position",
+      _gap_b.inputs_ok is False and _gap_a.inputs_ok is False
+      and _gap_b.site_sign_wd.tripped is False
+      and _gap_a.site_sign_wd.tripped is False
+      and [i.sign_wd.tripped for i in _gap_b.inverters] == [False, True]
+      and [i.sign_wd.tripped for i in _gap_a.inverters] == [True, False])
+check("⚠️ A LATCHED UNIT TAKES THE ROSTER PAST THE STALE-INPUT HOLD FROM EITHER "
+      "POSITION. Neither cycle parks on `inputs missing`; both go on to file "
+      "claims, and the latched unit is commanded 0 W by its OWN `failsafe` "
+      "claim, named in the allocation record. Grade this with "
+      "`self.inverters[:1]` and the B-latched run returns early - the +4-byte "
+      "mutation that was GREEN across all 19 files - and with "
+      "`self.inverters[-1:]` the A-latched run does. The remedy stops acting "
+      "the moment a poll is missed, which is main.py's own sentence for it",
+      not (_gap_b.reason or "").startswith("inputs missing")
+      and not (_gap_a.reason or "").startswith("inputs missing")
+      and _gap_b.inverters[1].target == 0.0
+      and _gap_a.inverters[0].target == 0.0
+      and all(any(p.unit == c.inverters[i].name and "failsafe" in p.why
+                  for p in (c.allocation.plans if c.allocation else ()))
+              for c, i in ((_gap_b, 1), (_gap_a, 0))))
+# ...and the counterfactual, which is what makes the two lines above a
+# DIFFERENCE rather than a description: with NOTHING latched, the very same
+# input gap DOES park the site on the hold. Without this the checks above would
+# be satisfied by a `cycle()` that never had a hold at all.
+async def _gap_no_latch():
+    c = _sign_site(_SignHass(load_w=2000.0))
+    await _drive(c, n=2)
+    c.inverters[0].soc = None
+    c.inputs_bad_since = datetime.now(timezone.utc)
+    await c.cycle()
+    return c
+
+
+_gap_none = asyncio.run(_gap_no_latch())
+print(f"       nothing latched, same gap: reason={_gap_none.reason!r}")
+check("...and the counterfactual (habit 7): with NO unit latched the SAME gap "
+      "DOES hold the site - `inputs missing 0s` - so the two runs above show "
+      "the latch carrying the roster past a hold that is really there, rather "
+      "than a hold that never fires",
+      (_gap_none.reason or "").startswith("inputs missing")
+      and not any(i.sign_wd.tripped for i in _gap_none.inverters))
+
+# --- and the SECOND survivor: the status vocabulary publish() hands the broker
+# ⚠️ THE EXISTING CHECK IS AT A ROSTER OF ONE, which is why this one exists.
+# "MQTT's controller-status sensor reports 'failsafe'" above drives a
+# single-inverter Controller, where `self.inverters[:1]` is the whole roster.
+# A site at 0 W reporting `running` is the failure main.py's comment names, and
+# at two inverters it is reachable whenever the latched unit is not the one a
+# narrowed reduction happens to read.
+_pub = {}
+
+
+def _published(ctl):
+    _pub.clear()
+    ctl.mqtt = type("P", (), {"enabled": True,
+                              "publish": lambda _s, v: _pub.update(v),
+                              "close": lambda _s: None})()
+    ctl.publish()
+    return dict(_pub)
+
+
+_pb, _pa = _published(_gap_b), _published(_gap_a)
+_pn = _published(_gap_none)
+print(f"       published status: B latched -> {_pb.get('status')!r}, "
+      f"A latched -> {_pa.get('status')!r}, none latched -> "
+      f"{_pn.get('status')!r}")
+check("⚠️ AND `publish()` SAYS `failsafe` WHICHEVER UNIT IS LATCHED. The status "
+      "sensor is the vocabulary every dashboard already reads, and a site with "
+      "one inverter parked by its own failsafe claim reporting `running` is "
+      "the exact failure main.py's comment names. `self.inverters[:1]` "
+      "publishes `running` on the B-latched site - +4 bytes, GREEN across all "
+      "19 files - and `self.inverters[-1:]` does it on the A-latched one",
+      _pb.get("status") == "failsafe" and _pa.get("status") == "failsafe")
+check("...and the counterfactual: the same two-inverter site with NOTHING "
+      "latched publishes `running`, so the two above are a difference the "
+      "reduction produced and not a constant",
+      _pn.get("status") == "running" and _gap_none.auto is True)
+
+# --- and the THIRD one the same enumeration found: the OPERATOR'S BANNER -----
+# ⚠️ `status_payload()`'s failsafe branch is a fourth `any(... for i in
+# self.inverters)`, and `self.inverters[:1]` there was +4 bytes and GREEN across
+# all 19 files too - for the third time, because the only fixture that reached
+# it was a roster of ONE. The banner is the ONE sentence at the top of the page;
+# a site holding an inverter at 0 W under a "Stopped" or "NOT READY" headline
+# sends the operator to the wrong question.
+_bn_b = _gap_b.status_payload()
+_bn_a = _gap_a.status_payload()
+_bn_n = _gap_none.status_payload()
+print(f"       banner: B latched -> {_bn_b['banner']!r}")
+print(f"               A latched -> {_bn_a['banner']!r}")
+print(f"               none      -> {_bn_n['banner']!r}")
+check("⚠️ AND THE BANNER LEADS WITH THE FAILSAFE WHICHEVER UNIT IS LATCHED, at "
+      "level `bad`, with the N>=2 sentence that names the unit's OWN measured "
+      "power rather than the meter. `self.inverters[:1]` drops the headline on "
+      "the B-latched site and `self.inverters[-1:]` on the A-latched one, and "
+      "the page then leads with whatever the next branch says",
+      _bn_b["level"] == _bn_a["level"] == "bad"
+      and _bn_b["banner"] == _bn_a["banner"]
+      and _bn_b["banner"].startswith("FAILSAFE")
+      and "its own measured power" in _bn_b["banner"])
+check("...and the counterfactual again: the same site with nothing latched "
+      "carries neither that level nor that sentence, so the banner really is "
+      "being produced by the reduction under test",
+      not _bn_n["banner"].startswith("FAILSAFE")
+      and _bn_n["banner"] != _bn_b["banner"])
+
 print()
 if fails:
     print(f"{len(fails)} FAILED: {', '.join(fails)}")

goodwe_controller/tools/supervisor_shape_probe.py

@@ -40,8 +40,24 @@ DECISIONS/CFG-04-inverter-roster.md:
      reconstruction happens to lack FIRST, which is an artefact of the
      reconstruction and NOT evidence about `inverters`. B is that evidence.
   C. A two-inverter blob validates, per-entry types enforced.
-  D. An entry missing `name`, `setpoint_entity` or `max_w` is refused BY NAME,
-     and a JSON string where the list belongs is refused outright.
+  D. An entry missing `name`, `setpoint_entity`, `max_w` or `bms_soc_floor` is
+     refused BY NAME - one key varied from an ACCEPTED baseline, and the key's
+     own name asserted in the refusal - and a JSON string where the list belongs
+     is refused outright.
+
+⚠️ RE-RUN 2026-09-04 FOR SAFETY-32, which made `bms_soc_floor` a REQUIRED
+per-entry key. That change broke §C and, worse, left §D printing PASS on a
+refusal about the WRONG KEY - the exact decay MUTATION.md habit 8 describes. §C
+now carries the key and §D is an isolated counterfactual asserting the key name.
+
+⚠️ RE-RUN AGAIN 2026-09-05, on the same 2026.08.0 image, because SAFETY-32's
+rebase onto SPIKE-04a merged two independent edits into §C and §D - the required
+`bms_soc_floor` and inverter B's datasheet `max_w: 4600`. A transcript stitched
+together by hand from two runs is not a measurement, so this one was measured:
+`all cases passed`, exit 0. B's 4600 W is STILL its DATASHEET figure and not a
+reading off any unit, and B's `bms_soc_floor: 15` in §C is illustrative - it
+differs from A's 10 so that the per-entry number is exercised at all, while
+production is expected to have BOTH packs at 10 %.
 """
 import sys, json, copy
 sys.path.insert(0, "/usr/src/supervisor")
@@ -145,13 +161,47 @@ show("the same blob MERGED with these defaults - what App.options actually is",
      f"max_w={out.get('max_w')!r}" if ok else out)
 
 print("\n== C. AC2: a two-inverter blob an operator would POST ==")
+# ⚠️ B's 4600 W IS FROM ITS DATASHEET, NOT A PLACEHOLDER AND NOT A MEASUREMENT.
+# SPIKE-04a (2026-09-04) identified inverter B from the owner's model number and
+# serial - a GoodWe GW5048D-ES, serial `55048ESU22AW0992` - and the datasheet's
+# Max. Charging / Discharging Power is 4600 W. The 3000 W that stood here was a
+# hypothesis from before the unit was known and was simply wrong; the 5000 VA AC
+# nameplate is wrong for this purpose too, because nothing will be connected to
+# B's MPPTs so the battery path is the ceiling. See goodwe/NOTES.md §1.1b.
+#
+# ⚠️ AND IT IS STILL NOT MEASURED. The datasheet prints 4600 W under BATTERY
+# INPUT DATA, so it is probably DC, while `max_w` is graded against 0x0518 - the
+# inverter's own AC power. If it is DC the AC ceiling is nearer 4600 x 0.94 =
+# 4324 W. NOTES.md §1.1b records both readings without picking one, and
+# SAFETY-20's `min(max_w, dev_max)` is what bounds it correctly once dev_max is
+# read off the unit. So this blob is what an operator would POST TODAY, not a
+# claim about what inverter B will turn out to do.
+#
+# ⚠️ THE TWO RATINGS ARE STILL DIFFERENT (5000 / 4600) AND MUST STAY DIFFERENT.
+# This file's own §B is the record of what an instrument that cannot distinguish
+# its two cases is worth. Note that 5000/4600 is a much NARROWER separation than
+# the 5000/3000 it replaces - fine here, where nothing computes on the numbers,
+# and NOT fine in the test fixtures, which is why those keep a wide illustrative
+# pair instead of the real one.
+#
+# ⚠️ AND `bms_soc_floor` IS A REQUIRED PER-ENTRY KEY SINCE SAFETY-32, so this
+# blob is also what proves an operator can still POST a two-inverter config
+# after that. THE TWO FLOORS DIFFER ON PURPOSE (10 and 15): equal values would
+# not exercise a per-entry number at all, for the same reason the two ratings
+# must stay different.
+# ⚠️ NEITHER OF B'S NUMBERS IS A MEASUREMENT OF A PACK. Only inverter A's 10 %
+# is read off hardware (register 0x0560 on the reference GW5000S-BP). B's 4600 W
+# is its DATASHEET figure and B's 15 % is an illustrative value chosen to differ
+# - there is no second pack on this site, and in production BOTH packs are
+# expected to floor at 10 %, which is why the differing pair lives here and in
+# the fixtures rather than in config.yaml's example.
 TWO = dict(LIVE, setpoint_entity="", inverters=[
     {"name": "inverter-a", "setpoint_entity": "number.goodwe_a_setpoint_w",
      "soc_entity": "sensor.goodwe_a_soc", "batt_entity": "sensor.goodwe_a_battery_power",
-     "max_w": 5000},
+     "max_w": 5000, "bms_soc_floor": 10},
     {"name": "inverter-b", "setpoint_entity": "number.goodwe_b_setpoint_w",
      "soc_entity": "sensor.goodwe_b_soc", "batt_entity": "sensor.goodwe_b_battery_power",
-     "max_w": 3000}])
+     "max_w": 4600, "bms_soc_floor": 15}])
 ok, out = validate(MERGER.merge(copy.deepcopy(defaults), copy.deepcopy(TWO)))
 show("two inverters", ok, json.dumps(out.get("inverters")) if ok else out)
 # The validated blob, for anyone who wants to POST it. Optional: the probe's
@@ -162,14 +212,38 @@ except OSError:
     pass
 
 print("\n== D. what the schema itself refuses, per entry ==")
-for title, entry in (
-        ("no name", {"setpoint_entity": "number.b", "max_w": 3000}),
-        ("no setpoint_entity", {"name": "inverter-b", "max_w": 3000}),
-        ("no max_w", {"name": "inverter-b", "setpoint_entity": "number.b"}),
-        ("max_w over the range", {"name": "inverter-b", "setpoint_entity": "number.b", "max_w": 9999})):
-    ok, out = validate(dict(TWO, inverters=[entry]))
-    show(f"an entry with {title} is refused", not ok, out)
-ok, out = validate(dict(TWO, inverters="[]"))
+# ⚠️ ONE KEY VARIED FROM AN ACCEPTED BASELINE, AND THE REFUSAL IS ASSERTED BY
+# NAME - §B's two lessons, applied here because SAFETY-32 is what broke this
+# section. These entries used to omit several keys at once and assert a bare
+# `not ok`; the moment `bms_soc_floor` became required, the "no max_w" case went
+# on printing PASS while the refusal it printed said `Missing option
+# 'bms_soc_floor'`. A refusal of unknown provenance is not a measurement of
+# anything, so the baseline below is COMPLETE and each case deletes exactly one
+# key - or, for the range case, moves exactly one value out of range.
+D_FULL = {"name": "inverter-b", "setpoint_entity": "number.b", "max_w": 4600,
+          "bms_soc_floor": 10}
+# MERGED with the shipped defaults, exactly as §C is and as App.options is: the
+# raw LIVE blob is missing root keys unrelated to this section (`maintenance_
+# start_hour` on the run that caught it), and a baseline refused for one of THOSE
+# is the provenance problem §B2 is kept as a warning about.
+D_BASE = MERGER.merge(copy.deepcopy(defaults), copy.deepcopy(TWO))
+ok, out = validate(dict(D_BASE, inverters=[D_FULL]))
+show("the per-entry BASELINE is ACCEPTED, so every refusal below has nowhere "
+     "else to come from", ok, json.dumps(out.get("inverters")) if ok else out)
+for title, entry, expect in (
+        ("no name", {k: v for k, v in D_FULL.items() if k != "name"}, "name"),
+        ("no setpoint_entity",
+         {k: v for k, v in D_FULL.items() if k != "setpoint_entity"}, "setpoint_entity"),
+        ("no max_w", {k: v for k, v in D_FULL.items() if k != "max_w"}, "max_w"),
+        ("no bms_soc_floor (SAFETY-32)",
+         {k: v for k, v in D_FULL.items() if k != "bms_soc_floor"}, "bms_soc_floor"),
+        ("max_w over the range", dict(D_FULL, max_w=9999), "at most 5000"),
+        ("bms_soc_floor over the range (SAFETY-32)",
+         dict(D_FULL, bms_soc_floor=99), "at most 50")):
+    ok, out = validate(dict(D_BASE, inverters=[entry]))
+    show(f"an entry with {title} is refused, and the refusal NAMES it",
+         (not ok) and expect in str(out), out)
+ok, out = validate(dict(D_BASE, inverters="[]"))
 show("a JSON STRING where the list belongs is refused", not ok, out)