feat: server telemetry, update entity, sync-clock controls

- Server device exposing CPU/RAM/GPU/temperature/battery sensors via
  /api/v1/system/performance, plus last-restart timestamp (cached with
  jitter threshold so the recorder doesn't see poll wobble) and version.
- Update entity backed by /api/v1/system/update — installs via
  /apply, hides the install button when the server reports
  can_auto_update=false.
- Sync-clock entities: reset button, speed number, running switch, and
  the event listener now refreshes on entity_changed events too.
- Bump manifest to 0.4.0.

custom_components/ledgrab/__init__.py

@@ -35,6 +35,7 @@ PLATFORMS: list[Platform] = [
     Platform.SENSOR,
     Platform.NUMBER,
     Platform.SELECT,
+    Platform.UPDATE,
 ]
 
 
@@ -61,6 +62,25 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     # Create device entries for each target and remove stale ones
     device_registry = dr.async_get(hass)
     current_identifiers: set[tuple[str, str]] = set()
+
+    # Server device — owns the system telemetry sensors (CPU, RAM, GPU, etc.)
+    server_identifier = (DOMAIN, f"{entry.entry_id}_server")
+    sw_version = (
+        coordinator.server_version
+        if coordinator.server_version and coordinator.server_version != "unknown"
+        else None
+    )
+    device_registry.async_get_or_create(
+        config_entry_id=entry.entry_id,
+        identifiers={server_identifier},
+        name=server_name,
+        manufacturer="LedGrab",
+        model="Server",
+        sw_version=sw_version,
+        configuration_url=server_url,
+    )
+    current_identifiers.add(server_identifier)
+
     if coordinator.data and "targets" in coordinator.data:
         for target_id, target_data in coordinator.data["targets"].items():
             info = target_data["info"]
@@ -93,6 +113,20 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
         )
         current_identifiers.add(scenes_identifier)
 
+    # One device per sync clock — groups its switch/number/button/sensor.
+    sync_clocks = coordinator.data.get("sync_clocks", []) if coordinator.data else []
+    for clock in sync_clocks:
+        clock_identifier = (DOMAIN, clock["id"])
+        device_registry.async_get_or_create(
+            config_entry_id=entry.entry_id,
+            identifiers={clock_identifier},
+            name=clock.get("name", clock["id"]),
+            manufacturer=server_name,
+            model="Sync Clock",
+            configuration_url=server_url,
+        )
+        current_identifiers.add(clock_identifier)
+
     # Remove devices for targets that no longer exist
     for device_entry in dr.async_entries_for_config_entry(device_registry, entry.entry_id):
         if not device_entry.identifiers & current_identifiers:
@@ -106,28 +140,37 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
         DATA_EVENT_LISTENER: event_listener,
     }
 
-    # Track target and scene IDs to detect changes
+    # Track target, scene, and sync-clock IDs to detect changes
     known_target_ids = set(coordinator.data.get("targets", {}).keys() if coordinator.data else [])
     known_scene_ids = set(
         p["id"] for p in (coordinator.data.get("scene_presets", []) if coordinator.data else [])
     )
+    known_clock_ids = set(
+        c["id"] for c in (coordinator.data.get("sync_clocks", []) if coordinator.data else [])
+    )
 
     def _on_coordinator_update() -> None:
-        """Detect target/scene list changes and trigger reload."""
-        nonlocal known_target_ids, known_scene_ids
+        """Detect target/scene/clock list changes and trigger reload."""
+        nonlocal known_target_ids, known_scene_ids, known_clock_ids
 
         if not coordinator.data:
             return
 
         targets = coordinator.data.get("targets", {})
 
-        # Reload if target or scene list changed
+        # Reload if target, scene, or sync-clock list changed
         current_ids = set(targets.keys())
         current_scene_ids = set(p["id"] for p in coordinator.data.get("scene_presets", []))
-        if current_ids != known_target_ids or current_scene_ids != known_scene_ids:
+        current_clock_ids = set(c["id"] for c in coordinator.data.get("sync_clocks", []))
+        if (
+            current_ids != known_target_ids
+            or current_scene_ids != known_scene_ids
+            or current_clock_ids != known_clock_ids
+        ):
             known_target_ids = current_ids
             known_scene_ids = current_scene_ids
-            _LOGGER.info("Target or scene list changed, reloading integration")
+            known_clock_ids = current_clock_ids
+            _LOGGER.info("Target, scene, or sync-clock list changed, reloading integration")
             hass.async_create_task(hass.config_entries.async_reload(entry.entry_id))
 
     coordinator.async_add_listener(_on_coordinator_update)