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/hass.py

@@ -16,6 +16,38 @@ _LOG = logging.getLogger("goodwe.hass")
 CORE_API = "http://supervisor/core/api"
 SUPERVISOR_API = "http://supervisor"
 BAD_STATES = ("unknown", "unavailable", "none", "")
+# What the Supervisor's proxy answers while Home Assistant restarts.
+UNAVAILABLE = (502, 503, 504)
+
+
+class Outage:
+    """UX-10: Home Assistant not answering, said in one plain line per outage.
+
+    A restart takes the REST API and the meter websocket down together, and
+    each used to log the library's own text for every entity and service
+    ("502, message='Bad Gateway', url=URL(...)", "Received message 8:1000 is
+    not str"). Now the first channel to fail says it once at WARNING, the raw
+    text goes to DEBUG, and the last channel to recover says so at INFO.
+    """
+
+    def __init__(self):
+        self.down_on = set()
+
+    def down(self, channel: str, what: str, detail) -> None:
+        if not self.down_on:
+            _LOG.warning("Home Assistant is not answering (%s), perhaps it is "
+                         "restarting. The add-on keeps trying.", what)
+        self.down_on.add(channel)
+        _LOG.debug("Home Assistant not answering on %s: %s", channel, detail)
+
+    def up(self, channel: str) -> None:
+        if channel in self.down_on:
+            self.down_on.discard(channel)
+            if not self.down_on:
+                _LOG.info("Home Assistant answers again.")
+
+
+OUTAGE = Outage()
 
 
 class HomeAssistant:
@@ -58,10 +90,18 @@ class HomeAssistant:
             async with self.session.get(
                 f"{CORE_API}/states/{entity_id}", headers=self._headers, timeout=10
             ) as resp:
+                if resp.status in UNAVAILABLE:
+                    OUTAGE.down("api", f"error {resp.status}",
+                                f"read {entity_id}: {resp.status}")
+                    return None
+                OUTAGE.up("api")
                 if resp.status == 404:
                     return None
                 resp.raise_for_status()
                 obj = await resp.json()
+        except aiohttp.ClientConnectionError as err:
+            OUTAGE.down("api", "no connection", f"read {entity_id}: {err}")
+            return None
         # SAFETY-61: an undecodable body is an absence like any other failed
         # read, never an exception into the control loop.
         except (aiohttp.ClientError, TimeoutError, ValueError) as err:
@@ -113,6 +153,11 @@ class HomeAssistant:
                 f"{CORE_API}/services/{domain}/{service}",
                 headers=self._headers, json=data, timeout=10,
             ) as resp:
+                if resp.status in UNAVAILABLE:
+                    OUTAGE.down("api", f"error {resp.status}",
+                                f"service {domain}.{service}: {resp.status}")
+                    return False
+                OUTAGE.up("api")
                 if resp.status >= 400:
                     body = await resp.text()
                     # 400 here usually means out-of-range for the entity - the
@@ -124,6 +169,10 @@ class HomeAssistant:
                                domain, service, resp.status, body[:200])
                     return False
                 return True
+        except aiohttp.ClientConnectionError as err:
+            OUTAGE.down("api", "no connection",
+                        f"service {domain}.{service}: {err}")
+            return False
         # ValueError: an undecodable error body (SAFETY-61) is a failed write.
         except (aiohttp.ClientError, TimeoutError, ValueError) as err:
             self._moan(f"svcerr:{domain}.{service}", "service %s.%s failed: %s",