connection
A StateFlow that emits the current ConnectionState of this state machine.
Observers can collect this flow to react to connection state changes. The flow emits the current state immediately upon collection.
Possible states:
ConnectionState.Disconnected: Not connected to the device.
ConnectionState.Connecting: Connection attempt in progress.
ConnectionState.Connected: Physical connection established.
ConnectionState.DiscoveringServices: Service discovery in progress.
ConnectionState.Ready: Device is ready for BLE operations.
ConnectionState.Error: An error occurred with a descriptive message.