- Add AudioFocusManager: holds audio focus for entire conversation
with 4-second grace period after TTS finishes
- Default to MODE_PAUSE (AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE) so
stereo fully stops instead of just ducking
- Wire into VoiceLoop: acquire on PTT, schedule release on TTS done,
immediate release on wrap-up and destroy
- Remove per-utterance focus from TTSManager (was causing stereo
to bounce on/off between each exchange)
- Add musicBehavior property to AppConfig (pause/duck/none)
spirit
a14c885e38