Introduces the MqttController, a new class that manages all communication with the MQTT broker.
On startup, it connects to the broker and publishes discovery configurations for all entities, automatically creating them in Home Assistant.
Subscribes to command topics to receive instructions from the HA interface.
Subscribes to state topics to read retained messages on startup, ensuring all user settings are persistent.
Acts as a bridge, translating incoming MQTT messages into internal EventBus events for other components to act upon.
