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/app/selfconfig.py

@@ -131,11 +131,16 @@ class SaveRefused(Exception):
     own sentences, byte for byte; `changed` names the keys that moved.
     """
 
-    def __init__(self, kind, problems=(), changed=(), stored=None):
+    def __init__(self, kind, problems=(), changed=(), stored=None,
+                 moved=None):
         self.kind = kind
         self.problems = list(problems)
         self.changed = list(changed)
         self.stored = stored
+        # UX-13 P4: the keys the OTHER surface changed - stored-on-open
+        # against stored-now - when the caller knows what it opened. None
+        # when it does not. `changed` also holds the operator's own edits.
+        self.moved = None if moved is None else list(moved)
         super().__init__(f"save refused ({kind})")
 
 
@@ -359,7 +364,7 @@ async def problems_and_ranges(opts: dict, hass=None, notes=None):
 
 
 async def save(selfcfg: SelfConfig, proposed: dict, expect: str, *,
-               hass=None) -> dict:
+               hass=None, base=None) -> dict:
     """Validate, compare-and-swap, then write. Refuse rather than half-do.
 
     Returns `{"fingerprint": <the new one>}` on success. Raises `SaveRefused`
@@ -382,6 +387,11 @@ async def save(selfcfg: SelfConfig, proposed: dict, expect: str, *,
     genuinely wants what the other surface wrote replaced, the page reloads,
     shows them what changed, and they save again from THAT - which is a
     decision made in front of the difference rather than through it.
+
+    `base`, when given, is the blob the page opened (the one `expect` is the
+    fingerprint of). A stale refusal then also names the keys that moved
+    underneath it, so the page does not list the operator's own edits among
+    the settings "changed elsewhere" (UX-13 P2 test, finding a).
     """
     problems = await problems_for(proposed, hass)
     if problems:
@@ -395,10 +405,15 @@ async def save(selfcfg: SelfConfig, proposed: dict, expect: str, *,
     actual = fingerprint(stored)
     if actual != expect:
         changed = changed_keys(stored, proposed)
+        moved = (changed_keys(base, stored)
+                 if isinstance(base, dict) and fingerprint(base) == expect
+                 else None)
+        keys = changed if moved is None else moved
         _LOG.warning("The settings page did not save, because the settings "
                      "changed while it was open (keys: %s).",
-                     ", ".join(changed) or "none this page also edited")
-        raise SaveRefused("stale", changed=changed, stored=stored)
+                     ", ".join(keys) or "none this page also edited")
+        raise SaveRefused("stale", changed=changed, stored=stored,
+                          moved=moved)
 
     await selfcfg.write_options(proposed)
     _LOG.info("options saved from the ingress panel; a restart is needed "