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/validate.py

@@ -343,6 +343,30 @@ from .watchdog import SIGN_OPTION_DEFAULTS
 
 _LOG = logging.getLogger("goodwe.config")
 
+
+class _WarnOnce(logging.Filter):
+    """UX-10: a settings warning is said once per start. The validator runs
+    twice at start (before the first cycle and again once the inverter's range
+    is known), and a warning about options that have not changed is the same
+    news both times. Refusals are ERROR and pass untouched."""
+
+    def __init__(self):
+        super().__init__()
+        self.seen = set()
+
+    def filter(self, record):
+        if record.levelno != logging.WARNING:
+            return True
+        text = record.getMessage()
+        if text in self.seen:
+            return False
+        self.seen.add(text)
+        return True
+
+
+WARN_ONCE = _WarnOnce()
+_LOG.addFilter(WARN_ONCE)
+
 # ⚠️ A MIRROR OF A FIRMWARE CONSTANT, AND IT CANNOT BE IMPORTED. The firmware
 # threshold is a compile-time YAML substitution baked into the ESP32 image
 # (`max_age_s: "30"`, master/goodwe-master-stage4-failsafe.yaml), so nothing at
@@ -1314,12 +1338,11 @@ def _price_problems(opts: dict) -> list[str]:
         if profile is not None and profile.product is not None \
                 and len(set(profile.prices)) == 1:
             _LOG.info(
-                "static_profile carries one distinct price (%.4f EUR/kWh "
-                "all-in), so this site is priced as FULLY FIXED. Arbitrage is "
-                "off by arithmetic - a flat series has no spread - and the "
-                "add-on runs self-consumption only, which is §9.2's handling "
-                "for this product. Peak shaving, reserve management and the "
-                "maintenance cycle are unaffected.", profile.prices[0])
+                "static_profile has one price (%.4f EUR/kWh all-in), so this "
+                "site has a fully fixed price. A flat price has no spread to "
+                "trade on, so the add-on uses the battery for self-consumption "
+                "only. Peak limiting, the reserve and battery maintenance are "
+                "not affected.", profile.prices[0])
 
     # ⚠️ TARIFF-17: THE TAXES PERIOD TABLE, PARSED AT STARTUP RATHER THAN AT
     # 03:00, FOR `static_profile`'s REASON ONE OPTION OVER. This table is read
@@ -1505,9 +1528,9 @@ def _price_problems(opts: dict) -> list[str]:
             _LOG.info(
                 "%s is set: injection priced as (%g x index %+g) x "
                 "(1 + %g/100) %s, i.e. %.4g x the wholesale price with a "
-                "%+.5f EUR/kWh offset. ⚠️ NO STRATEGY IN THIS ADD-ON READS "
-                "IT: arbitrage.py prices the sell side as displaced IMPORT "
-                "and compares two all-in CONSUMPTION prices, so this option "
+                "%+.5f EUR/kWh offset. No part of the add-on reads it yet: "
+                "trading prices the sell side as displaced import and "
+                "compares two all-in consumption prices, so this setting "
                 "changes no decision the add-on takes today. It is what you "
                 "are shown, and the shape a future export-aware strategy "
                 "would read.",