CFG-04: an operator can declare a second inverter, and the shape was measured

DEV-02 made every per-device value per-instance - rating, SoC, watchdogs,
heartbeat, store keys - so the code stopped assuming one inverter. The options
schema did not. `build_roster()` returned a list of exactly one and said so in
its own docstring, and there was no `inverters:` key for an operator to write,
so the roster could only ever be a roster of one.

THE SHAPE, AND WHY IT WAS MEASURED RATHER THAN CHOSEN

config.yaml had no list-of-objects anywhere, and `static_profile` carries a
whole tariff structure as a JSON string in a `str?` precisely because a nested
schema was doubted. That is a question about somebody else's software, so it was
answered by running it: `tools/supervisor_shape_probe.py` (committed) runs
Supervisor 2026.08.0's OWN `AppOptions` validator and `SCHEMA_APP_CONFIG`, out
of the release image, against this repository's config.yaml. 2026.08.0 is the
version the live install reports. The full transcript and the argument are in
DECISIONS/CFG-04-inverter-roster.md.

It accepts the list, enforces per-entry types, refuses a missing `name` /
`setpoint_entity` / `max_w` BY NAME, renders the option in the UI as a
repeatable section, and drops the key with a warning under an older schema - so
a downgrade is not the forward trap in reverse.

⚠️ AND THE `inverters: []` DEFAULT IS LOAD-BEARING, WHICH IS THE MEASUREMENT
THAT MATTERED MOST. Supervisor answers `Missing option 'inverters' in root` for
an options blob that has no such key - which every existing install's has, since
the key did not exist when they were written. `App.options` is the shipped
`options:` block deep-merged with the operator's stored one, so the empty
default is the difference between an upgrade nobody notices and an add-on that
cannot start with a schema pinned to the version that would fix it. That is
docs/deploy-rollback.md §4's trap in the FORWARD direction, found before it was
sprung. The merger was checked too: lists override rather than concatenate, so a
non-empty default could not have grown a roster behind the operator's back.

NOTHING IS INHERITED, WHICH IS DEV-02 RESTATED AS A CONFIG RULE

`name`, `setpoint_entity` and `max_w` are required of every entry. An entry that
omits `soc_entity` has no SoC sensor; it does not borrow the flat one. A
three-line fallback would have rebuilt the sibling-grading defect DEV-02 spent a
card removing, in YAML. Defaults still live in exactly one place (CFG-03):
there is no per-entry default anywhere, because there is no optional per-entry
number. A flat `setpoint_entity` left set beside a declared roster is refused
rather than ignored - it names an actuator nothing will write.

TWO PERMISSIVE READERS IN SHIPPED CODE, AND THREE MORE IN THE CHECKS

  validate.py rules 5 and 6 compared their thresholds against the FLAT `max_w`.
  At a roster of two 2000 W units with `max_w: 5000` left over from a
  single-inverter install, `sign_disagree_w: 3000` passed rule 5 while
  SAFETY-02's watchdog could fire on NEITHER unit - rule 5's own failure mode,
  reached through rule 5. They read `unit_caps()` now, which at one inverter is
  `[max_w]` exactly.

  main.py's `run_control()` re-ran the device-rating check behind
  `if self.o.get("setpoint_entity")` - the flat key, which a roster leaves blank
  - so on a two-inverter site no inverter's `max_w` was graded against the
  device it is written to, and the skip was silent. `validate_unit_ranges()`
  grades each unit against its own ESPHome and runs unconditionally.

  test_peakguard.py's `read_option()` and `_schema_bound()` and
  test_inverter.py's `read_schema_max()` matched a STRIPPED line and took the
  first hit, so the nested per-inverter `max_w:` began outranking the flat one -
  silently, and correctly, because the two bounds are the same int(100,5000)
  today. A reader that is right by coincidence is this project's named failure
  mode. All three are anchored at exactly two spaces now; the file's two halves
  disambiguate `peak_cap_w` instead of first-match, and an ambiguous key raises
  rather than picking one. test_tariff.py's copy of the idiom went with them.

THE AUDIT IS A CHECK, NOT A PROMISE

test_inverter.py part 11 finds every config.yaml-reading function in the suite -
transitively, because two of the readers CFG-04 had to change never name the
file - EXECUTES each against a synthetic two-inverter config.yaml whose
per-inverter numbers differ from its flat ones, and fails if any answers with
the per-inverter value. The table is not maintained by hand: the signature
decides, so the eleventh reader is named on its first run. config.yaml declares
`inverters:` BEFORE `max_w:` on purpose and part 11 asserts that ordering, so
the trap stays baited.

SAFETY-28's `actuator_writers()` needed no change - it was already a structural,
case-folding census - but until now there was no configuration in which two
writers on one actuator could be WRITTEN DOWN. There is now, and it is refused.

VERIFIED BY BREAKING IT

Ten mutations run through tools/mutation_run.sh and observed red, listed in
test_inverter.py part 12 with the check that bites each. Two survived the first
run and the CHECKS were changed, not the table: the inheritance check had blank
flat keys, so "inherited" and "not inherited" were the same empty string; and
the `run_control()` check asserted a SOURCE LINE was present, which re-indenting
it does not remove. Both are recorded in MUTATION.md's "the check's data cannot
reach the failure it names" section, which now carries two more habits: assert
on behaviour rather than on source text, and give a check whose failure mode is
a hang a deadline.

19/19 green in the goodwe-addon-ci image. The one-inverter path is byte-
identical: the whole existing suite runs unmodified against it.

Version bumped to 0.6.0 - the Supervisor keys the built image by `version:`, so
a schema change without a bump is a schema nobody reads.

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

goodwe_controller/test_validate.py

@@ -190,10 +190,26 @@ check("...and the refusal names the actuator and every writer aimed at it, so "
 # inconveniences, and then none of this is enforced. Two inverters with two
 # entities are two writers on TWO actuators, which is not the non-goal - it is
 # the whole point of the per-inverter roster.
+#
+# ⚠️ THE ENTRIES BELOW GAINED `name` AND `max_w` WHEN CFG-04 LANDED, AND THE
+# HAZARD FIXTURE ABOVE DELIBERATELY DID NOT. SAFETY-28 wrote both against a
+# shape that did not exist yet and guessed `id`; CFG-04 chose `name`, and made
+# `name`/`setpoint_entity`/`max_w` required of every entry (rule 9). The hazard
+# fixture is left in the OLD guessed shape on purpose - the claim it makes is
+# that `actuator_writers()` finds writers STRUCTURALLY, under a container and a
+# key spelling this file was never told, and rewriting it into today's shape
+# would quietly turn it into a check that the census knows about `inverters`.
+# This one is the opposite claim - that a real, valid, two-inverter config is
+# ACCEPTED - so it has to be a config the shipped validator actually accepts.
 _PER_INVERTER_OK = {k: v for k, v in base().items() if k != "setpoint_entity"}
 _PER_INVERTER_OK["inverters"] = [
-    {"id": "inverter-a", "setpoint_entity": "number.goodwe_setpoint"},
-    {"id": "inverter-b", "setpoint_entity": "number.goodwe_setpoint_b"}]
+    {"name": "inverter-a", "setpoint_entity": "number.goodwe_setpoint",
+     "max_w": 2000},
+    # ⚠️ 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.
+    {"name": "inverter-b", "setpoint_entity": "number.goodwe_setpoint_b",
+     "max_w": 2000}]
 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) == [])
@@ -219,11 +235,28 @@ check("...and entity ids are folded to lower case, so a second writer cannot "
       why(validate_startup_config(base(inverters=[{"setpoint_entity":
                                                    "NUMBER.GOODWE_SETPOINT"}]),
                                   -5000, 5000), "one actuator"))
+# ⚠️ THIS CHECK CHANGED SHAPE IN CFG-04, AND THE REASON IS A DECISION RATHER
+# THAN AN ADJUSTMENT. It used to assert that a blank per-inverter entity left
+# the whole config ACCEPTED - "blank is how an operator leaves a slot
+# unconfigured". CFG-04 decided that is not true of a ROSTER ENTRY: an entry
+# with no `setpoint_entity` is a unit that `allocator.plan()` still gives a
+# share of the site target to and that nothing can command, on a status page
+# reporting a site at full strength. Rule 9 refuses it by name. The claim about
+# the CENSUS is untouched and is now asserted directly on the census, where it
+# always belonged - a blank contributes no writer, so it cannot manufacture a
+# two-writer refusal out of two unconfigured slots.
 check("a BLANK per-inverter entity is not a writer - the same rule the scalar "
-      "key gets, since write_setpoint() returns immediately on a blank entity "
-      "and blank is how an operator leaves a slot unconfigured",
-      validate_startup_config(base(inverters=[{"setpoint_entity": "  "}]),
-                              -5000, 5000) == [])
+      "key gets, since write_setpoint() returns immediately on a blank entity",
+      actuator_writers(base(inverters=[{"setpoint_entity": "  "},
+                                       {"setpoint_entity": ""}]))
+      == {"number.goodwe_setpoint": ["setpoint_entity"]})
+check("...but the ENTRY is refused all the same, by rule 9 and not by the "
+      "census: a roster slot nothing can write still takes a share of the site "
+      "target every cycle and delivers none of it",
+      why(validate_startup_config(base(inverters=[{"name": "inverter-b",
+                                                   "max_w": 2000,
+                                                   "setpoint_entity": "  "}]),
+                                  -5000, 5000), "has no setpoint_entity"))
 
 # --------------------------------------------------------------------------- #
 print("3. a meter that can never read")