UX-13 P4: the setup wizard for installers

The Setup tab draws the Installer view's page model one step at a time,
from each field's `wizard` step in app/uilayout.py: meter (with the kettle
test), inverters and batteries, solar (optional), prices, peak limit
(battery modes: "comes in a later update", OPT-11), check and start.
It reuses P2's controls and saves through /config/validate and
/config/save. No route was added.

- First run: /config/model says `setup_needed` when the stored options name
  no power request entity, or on a new install (no `setup_done` and no
  `auto` in the Store, control not started). The page opens #setup only
  when opened with no route. The wizard's save writes `setup_done`.
- Kettle test: GET ha/entities?entity= reads one entity now, in W. The
  change decides: up keeps meter_invert off, down turns it on; a net or
  import/export meter that goes down blocks the step with what to check.
- Last step: validate.setup_checks() beside the refusals: the meter reads,
  each power request entity exists in HA (bad if not, SAFETY-77), battery
  levels and power with direction, solar sign, prices. Saves with
  shadow_mode on by default, then a confirmed restart naming the 0 W.
- P2 test finding (a): a stale save lists only the keys the other surface
  moved (the blob handed out on open, by fingerprint, against stored now).
- test_setup.py; tools/ux13_wizard_blobs.py makes the 88 blobs the wizard
  can save; all accepted by Supervisor 2026.08.0 AppOptions (offline).
- DECISIONS/UX-13-setup-wizard.md; DOCS "Setup, for a new install".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LyR88rXETvwhTgx6yHE39p

goodwe_controller/test_messages.py

@@ -920,7 +920,7 @@ DATA = {
     "price_history.py:messages.count(len(points), 'price')",
     "price_history.py:err",
     "selfconfig.py:messages.count(len(problems), 'problem')",
-    "selfconfig.py:', '.join(changed) or 'none this page also edited'",
+    "selfconfig.py:', '.join(keys) or 'none this page also edited'",
     "static_tariff.py:e", "store.py:err", "store.py:key", "store.py:raw",
     "tariff.py:self.path", "tariff.py:err", "tariff.py:start", "tariff.py:month",
     # validate.py: option values and keys (the refusals are part 3's)