When "page turn with volume buttons" is enabled, the volume keys were
intercepted for the whole reading session, so switching from reading to
TTS left them flipping pages instead of adjusting playback volume.
Gate the volume-key interception on this book's TTS playback state
(via the existing `tts-playback-state` bus): release interception while
TTS is playing so the OS handles volume, and re-acquire it when TTS is
paused or stopped. The acquire/release pair is keyed on the playback
state so the deviceStore reference count stays balanced.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Huang Xin
30727d353a