Dashboard creates the MQTT client and the HA device with the dummy "Uptime" sensor (D41) in overlay and both desktop modes, connects in started() and disconnects gracefully on aboutToQuit. The new platform mode --desktop-novr behaves like --desktop for now (D22). The main tab shows device, broker, connection state and last error (UI-1) through the ConnectionStatus QML singleton. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>