MQTT Publish Client

Implement a Python MQTT client that connects to a broker and publishes sensor data periodically. The client should maintain connection, handle disconnects, and support QoS 1.

Constraints

• Use paho-mqtt library.
• Broker: test.mosquitto.org.
• Topic: device/sensor.
• Publish every 2 seconds.
• Reconnect on disconnect.
• Use QoS level 1.