fix: mqtt subscription format

- Updated subscription format to use dict with topic and qos fields
- Fixed both _post_connect and subscribe methods

backend/mqtt_integration.py

@@ -102,8 +102,8 @@ class HomeAssistantMQTT:
         logger.info("Connected to MQTT broker")
         self._connected = True
         try:
-            # Subscribe to command topic
-            await self.client.subscribe([(self.command_topic, 1)])
+            # Subscribe to command topic using a dict
+            await self.client.subscribe([{'topic': self.command_topic, 'qos': 1}])
             logger.info(f"Subscribed to command topic: {self.command_topic}")
             
             # Publish discovery config
@@ -192,7 +192,7 @@ class HomeAssistantMQTT:
         """Subscribe to a topic"""
         if self.client and self._connected:
             try:
-                await self.client.subscribe([(topic, 0)])
+                await self.client.subscribe([{'topic': topic, 'qos': 1}])
             except Exception as e:
                 logger.error(f"Failed to subscribe to topic: {e}")