- Backend computes block_elapsed_seconds server-side from timer_events
- Store tracks blockStartedAt (ms) + blockElapsedOffset (seconds) instead
of a client-side counter; updated correctly on start/pause/resume/end
- TimerDisplay derives elapsed from store props so both views always agree
- Add compact timer display to dashboard session card
- Add isPaused/pause-resume logic to dashboard Pause/Resume buttons
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>