Implements the core mute functionality.
Adds a new MicMuteHandler class that subscribes to the set_mic_mute event. This handler updates the state.mic_muted flag and publishes secondary mic_muted or mic_unmuted events for LED feedback.
Modifies the process_audio function to check the state.mic_muted flag in its main loop, pausing audio processing when the flag is True.
Modifies the startup sequence to read the volume_level from the loaded preferences.
This saved value is then passed as the initial_volume when creating the music_player and tts_player instances.
Passes the event_bus and loop instances into the ServerState object upon creation.
Adds new command-line arguments (--led-interface, --led-clock-pin, --led-data-pin) to allow the user to select and configure the LED hardware interface at runtime.