- Wire publishListEvent fan-out in lists.ts after every write mutation (item:added/updated/deleted, list:updated/deleted)
- Add GET /api/sse/lists scoped endpoint in sse.ts: resolveUserId → 401 on null; getAccessibleListIds → subscribe only to accessible channels; 30s heartbeat; cleanup on disconnect (D-04/T-04-01/T-04-02)
- Create useListSSE.ts: bounded-backoff EventSource wrapper (250ms→500ms→1s→2s→4s→cap 8s); MAX_ATTEMPTS=6; withCredentials:true; close-before-retry prevents reconnect storm (Pitfall 3); invalidates ['list', listId] on open (D-10) and on each event; onStateChange('disconnected') after exhaustion (D-11)
- Create LiveSyncIndicator.tsx: connected=green dot; reconnecting=pulsing muted dot + label; disconnected=red dot + 'Updates paused' (role=alert); correct ARIA per UI-SPEC
- Wire useListSSE + LiveSyncIndicator into ListDetail header; retain refetchInterval:30000 polling fallback (D-12)
- All 8 useListSSE tests pass; all 54 API tests pass; both typechecks pass
- playwright-cli: live update confirmed (eggs item added via API appeared in browser without manual refresh)
Lucas Berger
1652a68c51