The user reported: when a 5-min meeting reminder fires and they hit
"Postpone 5 min", the second reminder appears at the new time but
**without sound** — and the only way to get the sound back is to leave
the app and come back (full tab reload).
Root cause: `UpcomingMeetingAlert` keeps a `playedRef: Set<number>` of
meeting ids that have already chimed, so the 30s polling/refetch
doesn't replay the chime over and over. The alert is mounted globally
in `App.tsx` and never unmounts during in-app navigation, so the Set
lives for the whole session. Postpone changes the meeting's
`startTime` but keeps the same `id`, so the second alert hit the
"already chimed" guard and stayed silent. Only a real tab reload
cleared the Set, which is exactly the workaround the user discovered.
Fix: change the dedupe key from `meeting.id` (number) to
`${meeting.id}:${startTime}` (string). Every postpone moves
startTime, so each post-postpone alert is treated as a fresh
instance and chimes again. The 3s throttle inside
`NotificationPlayer` still protects against burst-replay within the
same alert instance.
Untouched:
- `shownRef` — still keyed by id, because the server-side "shown"
audit row is one-per-meeting-per-user by design.
- `NotificationPlayer`, iOS unlock path, vibration, throttle.
- Postpone API surface and `PostponeDialog`.
Verified: `pnpm --filter @workspace/tx-os exec tsc --noEmit` clean.
riyadhafraa
ccb891d4ca