- RingtoneEditorScreen: 32-note step sequencer accessible via new Tools page on home screen. U/D=pitch, ENTER=octave cycle, L/R=cursor, MENU=options (play, duration, BPM, insert/delete, save). Notes stored packed in NodePrefs and persisted via DataStore.
- ToolsScreen: new "Tools" home page entry launching the editor
- Buzzer volume: 0-4 bar control in Settings > Sound, persisted to prefs
- Buzzer notifications: fixed notify() firing inside wrong serial-guard branch and before addChannelMsg set the channel index
- Unread counter: fixed newest-first index direction; watermark formula now correct
- OLED brightness: wider range via pre-charge register 0xD9 combined with contrast
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>