UX-10: the last plain-language leftovers: log lines, two table rows, 'Why: Other', red at 0 s

- test_messages.py part 6: every dynamic part of a WARNING+ line is classified
  as data or as a built text, and every built text is produced by the real
  code and checked. This is the gap the 2d scan had: it counted `%s` as one
  word, so reasons built by loop_clamp_note() and friends were never seen.
- Quoted reasons rewritten to STYLE.md (red-alarm shape, codes kept):
  OUTPUT_CLAMP, METER_FROZEN, CIRCULATING_POWER, STALE_READING, the peak
  guard (codes now PEAK_GUARD*), the migration report, price feed, price
  history and gate reasons. Plurals via messages.times()/count().
- Top table: Price history "96 prices over 24 hours for 26 Sep", Tariff
  "one every 15 minutes or every hour", "not final yet" dropped.
- Levels and noise: per-cycle shadow line DEBUG, shadow on/off INFO,
  aiohttp access log only at log level debug, settings warnings once per
  start, one plain line per Home Assistant outage (hass.Outage).
- INFO jargon and error texts: no "§8.3", ISO times, "banked", "keys ARE",
  "NOT_OBSERVED", "did NOT land", "AND".
- Display bugs: WHY_WINNER covers every winner and safety reason
  (main.why_key(), part 7 finds them in the code); the meter row is amber
  "waiting for the first reading" inside its limit after a start; the
  missing-reading age is counted when the page asks.
- STYLE.md and DECISIONS/UX-08-short-notifications.md (UX-10 section).

No change to safety behaviour, alarm levels, notification ids, triggers,
cadence or the banner cascade. One row colour changes (meter at start),
justified in DECISIONS.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

goodwe_controller/app/store.py

@@ -222,6 +222,8 @@ class MigrationReport:
         self.misdirected = []
         # Why nothing ran, when nothing ran. Empty means "already at schema".
         self.skipped = ""
+        # The inverter list the moves were graded against, for `explain()`.
+        self.roster = []
 
     @property
     def ok(self) -> bool:
@@ -237,19 +239,27 @@ class MigrationReport:
             # the flat keys ARE its namespace - and an operator reading the
             # startup log needs to be told which, because only one of them
             # changes when a second inverter is declared.
-            return self.skipped or (f"store already at schema "
-                                    f"{self.from_version}; no "
-                                    f"per-inverter migration needed")
-        out = (f"migrated {len(self.moved)} flat key(s) to inverter "
-               f"namespaces: " + ", ".join(sorted(self.moved)))
+            return self.skipped or (f"the saved state is already at version "
+                                    f"{self.from_version}, so nothing moves")
+        # UX-10: plain sentences (test_messages.py part 6). Each problem is
+        # named by its key and what went wrong, and `problems`, `lost` and
+        # `misdirected` keep their full notes for the checks that read them.
+        n = len(self.moved)
+        out = (f"moved {n} saved {'value' if n == 1 else 'values'} to one part "
+               f"per inverter: " + ", ".join(sorted(self.moved)) if n
+               else "moved nothing")
         if self.kept:
-            out += " (left alone, already namespaced: " + ", ".join(sorted(self.kept)) + ")"
-        if self.problems:
-            out += " - PROBLEMS: " + "; ".join(self.problems)
-        if self.lost:
-            out += " - STATE LOST: " + "; ".join(self.lost)
-        if self.misdirected:
-            out += " - WRONG NAMESPACE: " + "; ".join(self.misdirected)
+            out += ". Already in place: " + ", ".join(sorted(self.kept))
+        def keys(notes):
+            return ", ".join(note.split(" ", 1)[0] for note in notes)
+        other = [n for n in self.problems
+                 if n not in self.lost and n not in self.misdirected]
+        parts = ([f"lost {keys(self.lost)}"] if self.lost else []) + (
+            [f"moved under an inverter not in the list {self.roster!r}: "
+             f"{keys(self.misdirected)}"] if self.misdirected else []) + (
+            [f"read back differently {keys(other)}"] if other else [])
+        if parts:
+            out += ". Problems: " + ", and ".join(parts)
         return out
 
 
@@ -436,6 +446,7 @@ def _verify_moves(store, rep: MigrationReport, roster=None) -> None:
     if roster is None:
         return
     names = [str(n) for n in roster]
+    rep.roster = names
     # `unit_key()` builds `unit/<unit>/<key>`, so the unit is field 1. Split
     # through the same spelling the writer used rather than re-deriving it.
     #
@@ -469,8 +480,8 @@ def _verify_moves(store, rep: MigrationReport, roster=None) -> None:
         if unit in names:
             continue
         rep.verified = False
-        note = (f"{target} was migrated into namespace {unit!r}, which is NOT "
-                f"on the roster {names!r} - nothing reads that key")
+        note = (f"{target} was moved under {unit!r}, which is not in the "
+                f"inverter list {names!r}, so nothing reads it")
         rep.problems.append(note)
         rep.misdirected.append(note)
 
@@ -536,14 +547,13 @@ def migrate_maint_keys(store, unit: str, roster) -> MigrationReport:
     names = [str(n) for n in roster]
     rep.from_version = int(data.get(MAINT_SCHEMA_KEY, 0) or 0)
     if len(names) <= 1:
-        rep.skipped = ("one inverter: the flat maintenance keys ARE that pack's "
-                       "history and are read in place, so there is nothing to "
-                       "move and the store layout does not change")
+        rep.skipped = ("one inverter, so its maintenance history is read "
+                       "where it is and nothing moves")
         return rep
     if rep.from_version >= MAINT_SCHEMA_VERSION:
-        rep.skipped = (f"maintenance history already at schema "
-                       f"{rep.from_version}; written by a multi-inverter "
-                       f"version and not touched")
+        rep.skipped = (f"maintenance history already at version "
+                       f"{rep.from_version}, written for several inverters, so "
+                       f"it is left as it is")
         return rep
 
     rep.ran = True
@@ -567,8 +577,8 @@ def migrate_maint_keys(store, unit: str, roster) -> MigrationReport:
         # the re-run a no-op where the keys did land, so refusing the marker
         # costs one repeated pass and buys the difference between a migration
         # that can still be fixed and one the store says already happened.
-        _LOG.error("per-pack maintenance-history migration did NOT land and "
-                   "has not been marked done: %s", rep.explain())
+        _LOG.error("Moving the maintenance history to one part per inverter "
+                   "did not work, so it is not marked done: %s", rep.explain())
     return rep