TEL-12: several PV inverters, and one absent member is an absent TOTAL

0.11.0 shipped `pv_entity` as a single string. The reference site's owner
reported within minutes of it going live that they have several PV inverters
and could configure one - which is ordinary for a multi-string roof, not a
property of one house. `pv_entities` is the roster and the row carries the
SITE total.

⚠️ THE HARD PART IS ABSENCE, NOT THE LIST. Three configured, one `unavailable`,
and the sum of the other two is a SMALLER NUMBER INDISTINGUISHABLE FROM A REAL
ONE. Read back by OPT-10 that says "there was less PV than there was" - the "no
irradiance" conclusion the channel exists to TEST. So `pv.total()` answers
`None` the moment any configured entity is absent: the topic carries HA's own
`None`, the entity goes to `unknown`, the recorder records a GAP. The
alternative (the partial sum beside a contributor count) was implemented and
run as mutation N1b; it loses because the MQTT row is read COLD a week later by
an attribution that would believe it, while the qualifying count would live in a
second entity with its own history. The partial information is not thrown away -
the STATUS PAGE names every entity that reported, with its watts, and every one
that did not, with its reason, because that surface is read LIVE by a human who
wants the diagnostic.

⚠️ AND THE MIRROR: a member honestly reporting 0 W is SUMMED. The test is
`is None`, never falsiness - a roster that blanked the site on a zero would
report an absence on every clear evening.

THE SURFACE IS MEASURED, NOT PREFERRED. `pv_entity` could not become a list:
tools/supervisor_shape_probe.py §G shows Supervisor 2026.08.0 answering an
0.11.0 install's stored string with `Invalid list for option 'pv_entity'`, and
deepmerge's list strategy is `override` so a `[]` default does not rescue it -
the live add-on would not start. `match(.*)?` does accept both shapes and is
rejected for a different, measured reason: it validates nothing (a string, a
list and the integer 417 all pass) and renders as a plain text box. So
`pv_entities` joins `pv_entity` and REPLACES it when set, CFG-04's rule for
`inverters:`, with a status caution saying which key won - a union would
double-count the inverter the old key still names.

STILL NOT A CONTROL INPUT. tools/tel11_pv_trace.py was extended rather than
replaced and now grades five claims over three document sets. The control hash
is UNMOVED - 846a10a5b89e… on `unset` and on `one`, on both trees - and the
roster control document is byte-identical between the two trees. 2/5 is a claim
TEL-11 could not make: with 0.11.0 as the baseline, "one entity behaves exactly
as 0.11.0 does" is a real cross-tree identity over control AND telemetry.

⚠️ TEL-11's OWN `--compare` REFUSAL HAD TO CHANGE, and that is MUTATION.md habit
24: a discriminator defined as "the baseline lacks this feature" dies on the
release that ships the feature, and dies as a false refusal.

Twelve mutations, each on a fresh purged `cp -a`, no survivors. N5 is +0 B
(`sum` -> `max`, the same three characters) and was run on a fresh copy with
`cmp` confirming the edit on disk. The fixture is three distinct NON-ZERO
contributions in two units with absence driven at EVERY position - a member
contributing 0 W could go absent without moving the sum of the rest, which is
habit 23 with a coinciding value in the arithmetic rather than in the plant.

31/31 in the CI image. Not deployable as merged: config.yaml stays at 0.11.0,
so predeploy_check.py reports a NO-OP until PKG cuts a version. A CHANGELOG
entry is wanted and deliberately not written - 11b forbids `## Unreleased` and
the bump is PKG's call; DECISIONS/TEL-12-several-pv-inverters.md is the
material it needs.

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

goodwe_controller/translations/en.yaml

@@ -87,6 +87,9 @@ configuration:
   pv_entity:
     name: "Hardware · PV production entity (W)"
     description: "Optional, and MEASUREMENT ONLY - it changes no control behaviour whatsoever. Point it at your solar inverter's own power sensor (any brand Home Assistant reads; it does not have to be on the RS485 bus) and the add-on records production beside the grid and battery figures, so a day of unstored surplus can be told apart from a day with no sun. POSITIVE MUST MEAN PRODUCING. The unit is read from the entity itself - W, kW and the rest of Home Assistant's power units - so a sensor with no unit is refused rather than guessed at, and the status page says so. Leave it empty and nothing is read, nothing is published and nothing is shown."
+  pv_entities:
+    name: "Hardware · PV production entities, one per inverter (W)"
+    description: "Optional, and MEASUREMENT ONLY - it changes no control behaviour whatsoever. Use this instead of the single entity above when your roof has SEVERAL solar inverters: add one row per inverter, pointing at each one's own power sensor, and the add-on records the SITE total. Each entity's own unit is read, so a kW inverter beside a W one adds up correctly. ⚠️ SETTING THIS IGNORES THE SINGLE ENTITY ABOVE - clear that one when you fill this in, or you will see a caution on the status page saying so. ⚠️ AND IF ANY ONE OF THESE STOPS REPORTING THERE IS NO SITE TOTAL: the sensor goes to 'unknown' and the history records a gap, rather than publishing the sum of the ones that did answer. Two inverters out of three add up to a smaller number that looks exactly like a real one, and a week later that reads as 'there was less sun than there was' - which is the one conclusion this recording exists to test. The status page names which entity is missing, why, and what the others reported. Leave it empty and nothing is read, nothing is published and nothing is shown."
   meter_source:
     name: "Meter · Where the meter reading comes from"
     description: "'off' keeps the single Home Assistant entity below, which is what an existing installation runs on until you choose otherwise. ha_dsmr subscribes to the DSMR integration; mqtt_p1 reads an MQTT topic; ha_signed reads one signed entity, which is what a HomeWizard P1 publishes; homewizard_local polls the meter's own local API and skips Home Assistant entirely. ⚠️ Only homewizard_local can tell 'the meter has not answered' apart from 'the value has not changed', so it is the only source on which the frozen-meter alarm means anything."