User feedback: voice session should stop when leaving app or locking screen.
Previously:
- App goes to background → session stays active (broken state)
- STT/TTS cannot work in background anyway
- Wasted battery, confusing UX
Now:
- background/inactive → automatically stops session
- Cleans up all state (STT, refs, pending transcripts)
- User must manually restart via FAB when returning
Behavior:
User locks screen → session stops → FAB becomes gray
User switches app → session stops → clean state
User returns → must press FAB to start new session
app/(tabs)/_layout.tsx:238-256
Sergei
4bcb1f70c5