- Backend: GET /api/reminders/due endpoint, PATCH snooze endpoint, snoozed_until column + migration - Frontend: useAlerts hook polls every 30s, fires Sonner toasts on non-dashboard pages (max 3 + summary), renders AlertBanner on dashboard below stats row - Dashboard Active Reminders card filters out items shown in banner Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>