Server-side trails: the current run and one previous

The integration now records the path itself (trails.py): it watches the
source entity's state changes, so recording needs no open card, has no
multi-tab write races, and every screen sees the same line — reloads
included, which retires the localStorage snapshot after one day of
life. Stored per marker: the current run plus exactly one previous
(owner call — users want cleaned-vs-uncleaned at a glance). The
previous run renders at 40% opacity; the current one still trims its
live tail so it never outruns the puck. Runs rotate on start or map
switch, points cap at 2000 with decimation, store writes debounce 10 s,
and houseplan_trail_updated pushes live cards. TrailBook is pure under
5 backend tests; the WS command degrades silently on older backends.

custom_components/houseplan/__init__.py

@@ -50,6 +50,12 @@ async def async_setup_entry(hass: HomeAssistant, entry: HouseplanConfigEntry) ->
         raise ConfigEntryNotReady(f"House Plan storage is not readable: {err}") from err
     entry.runtime_data = data
 
+    # server-side vacuum trails: the integration records the path itself
+    from .trails import TrailRecorder
+    recorder = TrailRecorder(hass, data)
+    await recorder.async_setup()
+    hass.data[DOMAIN]["trail_recorder"] = recorder
+
     card_path = Path(__file__).parent / "frontend" / "houseplan-card.js"
     plans_path = Path(hass.config.path(PLANS_DIR))
     files_path = Path(hass.config.path(FILES_DIR))
@@ -194,6 +200,9 @@ async def async_setup_entry(hass: HomeAssistant, entry: HouseplanConfigEntry) ->
 
 
 async def async_unload_entry(hass: HomeAssistant, entry: HouseplanConfigEntry) -> bool:
+    rec = hass.data.get(DOMAIN, {}).pop("trail_recorder", None)
+    if rec:
+        rec.teardown()
     """Unload the entry.
 
     WS commands and the HTTP view are global (async_setup) and stay registered —