fix: mqtt qos constant

- Use integer 1 for QoS level instead of importing constant

backend/mqtt_integration.py

@@ -102,9 +102,8 @@ class HomeAssistantMQTT:
         logger.info("Connected to MQTT broker")
         self._connected = True
         try:
-            # Subscribe to command topic using gmqtt's Subscription class
-            from gmqtt.mqtt.constants import QOS_1
-            await self.client.subscribe([(self.command_topic, QOS_1)])
+            # Subscribe to command topic
+            await self.client.subscribe([(self.command_topic, 1)])
             logger.info(f"Subscribed to command topic: {self.command_topic}")
             
             # Publish discovery config