feat: Home Assistant integration — WebSocket connection, automation conditions, UI

Add full Home Assistant integration via WebSocket API:
- HARuntime: persistent WebSocket client with auth, auto-reconnect, entity state cache
- HAManager: ref-counted runtime pool (like WeatherManager)
- HomeAssistantCondition: new automation trigger type matching entity states
- REST API: CRUD for HA sources + /test, /entities, /status endpoints
- /api/v1/system/integrations-status: combined MQTT + HA dashboard indicators
- Frontend: HA Sources tab in Streams, condition type in automation editor
- Modal editor with host, token, SSL, entity filters
- websockets>=13.0 dependency added

server/pyproject.toml

@@ -46,6 +46,7 @@ dependencies = [
     "aiomqtt>=2.0.0",
     "openrgb-python>=0.2.15",
     "opencv-python-headless>=4.8.0",
+    "websockets>=13.0",
 ]
 
 [project.optional-dependencies]