- MainActivity: suppress toast when activity not resumed, auto-navigate to
Settings on new firmware
- SettingsActivity: unified BLE/USB radio buttons + single update button,
version check before OTA, show dialog before loadFirmware, spinner timeout
- BleRelayManager: expose getEspVersion()
- OtaManager: reduce chunk size 500→248 to fit BLE MTU 255
- ESP: WRITE→WRITE_NR on OTA characteristic (was silently dropping data)
- Layout/strings: remove intro text, add method radio buttons
- Bump all firmware versions to v5