Show each sensor's longest report gap; stop recording volatile attributes

Choosing room and weather freshness limits required knowing how long
each sensor normally goes without reporting, which HA does not show.
Add max_age_seconds_24h to every source in input_quality: the largest
report age seen at polls over the last 24 hours (hourly buckets, reset
on reload, underestimates by up to one poll interval).

input_quality and weather_comparison change every poll, so the Recorder
stored a new attribute row every five minutes. Mark them unrecorded;
they remain visible on the Status entity. Model coefficients and other
attributes are still recorded.

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

tests/ha/test_lifecycle.py

@@ -27,6 +27,11 @@ async def test_setup_reload_unload(hass, entry, inputs):
     assert len(entities) == 5
     ids = {e.unique_id: e.entity_id for e in entities}
     assert coordinator.data["status"] == "learning"
+    status = hass.states.get(ids[f"{entry.entry_id}_status"])
+    assert status.attributes["input_quality"]["rooms"]["sensor.room"]["max_age_seconds_24h"] == 0
+    # Volatile diagnostics stay visible but are not written to the Recorder.
+    assert {"input_quality", "weather_comparison"} <= status.state_info["unrecorded_attributes"]
+    assert "models" not in status.state_info["unrecorded_attributes"]
     proposal_id = registry.async_get_entity_id("binary_sensor", DOMAIN, f"{entry.entry_id}_proposal")
     assert hass.states.get(proposal_id).state == "unavailable"
     assert await hass.config_entries.async_reload(entry.entry_id)

tests/test_coordinator.py

@@ -524,3 +524,18 @@ class BoundaryTests(unittest.IsolatedAsyncioTestCase):
         self.c._store.async_load.return_value = {'retired_learners': retired}
         await self.c.async_restore_model()
         self.assertEqual(list(self.c._retired), [f'sensor.old{i}' for i in range(6, 30)])
+
+    async def test_report_gap_maximum_is_exposed_per_sensor(self):
+        await self.sample(2400)  # the room then stays silent for 40 minutes
+        self.states['sensor.outside'].last_reported = self.now
+        data = await self.sample()
+        room = data['input_quality']['rooms']['sensor.room']
+        self.assertEqual((room['status'], room['max_age_seconds_24h']), ('stale', 2400))
+        self.states['sensor.room'].last_reported = self.now
+        self.states['sensor.outside'].last_reported = self.now
+        data = await self.sample()
+        room = data['input_quality']['rooms']['sensor.room']
+        self.assertEqual((room['status'], room['age_seconds'], room['max_age_seconds_24h']),
+                         ('valid', 0, 2400))
+        weather = data['input_quality']['weather']['temperature']['sensor.outside']
+        self.assertEqual(weather['max_age_seconds_24h'], 0)  # kept reporting; tracked separately

tests/test_data_quality.py

@@ -31,6 +31,18 @@ class FreshnessTests(unittest.TestCase):
             with self.assertRaises(ValueError):
                 quality.freshness(now, now, limit)
 
+    def test_report_age_history_keeps_24_hour_maximum(self):
+        history = quality.ReportAgeHistory()
+        start = datetime(2026, 10, 26, tzinfo=timezone.utc)
+        self.assertEqual(history.observe('sensor.a', start, 2400), 2400)
+        self.assertEqual(history.observe('sensor.b', start, 60), 60)
+        for minutes in range(5, 24 * 60, 5):
+            result = history.observe('sensor.a', start + timedelta(minutes=minutes), 300)
+        self.assertEqual(result, 2400)  # still inside the 24-hour window
+        later = start + timedelta(hours=24, minutes=5)
+        self.assertEqual(history.observe('sensor.a', later, 300), 300)
+        self.assertEqual(history.observe('sensor.b', later, 30), 30)
+
     def test_freshness_settings_translated(self):
         for name in ('strings.json', 'translations/en.json', 'translations/ro.json'):
             data = json.loads((ROOT / name).read_text())