Settings > Timers offered a "Default duration", but nothing that creates a timer ever read it: the keypad starts empty. The row, its preference, ClockDefaults.timerDuration and the backup field are gone, and the screen's hint and the hub's subtitle now only speak of the sound. Backups no longer write default_timer_duration_millis. Older files that carry it still import, since the codec ignores unknown keys. Closes #5