docs: archive DASHBOARD_PLAN.md and update task tracking

- Move completed DASHBOARD_PLAN.md to docs/archive/
- Update COMPLETED.md with dashboard implementation details
- Update TODO.md to reflect dashboard completion
- Mark remaining dashboard features as optional Phase 4

docs/archive/COMPLETED.md

@@ -714,7 +714,102 @@ frontend/src/
 
 ---
 
-**Last Updated:** 2025-11-20 (Phase 3 completed - MVP finalized)
+---
+
+## ✅ Dashboard Implementation (COMPLETED 2025-11-21)
+
+**Status:** Core MVP complete + Optional enhancements
+**Time Spent:** ~6 hours
+**Commits:** 8 commits
+
+### Overview
+Centralized dashboard for logged-in users to:
+- View checked-in events with quick access to chats
+- Manage active matches and conversations
+- Track video exchange and rating status
+- Handle pending match requests
+
+**Route:** `/dashboard` (default landing page after login)
+
+### Backend Implementation
+- [x] ✅ **Dashboard API endpoint** `GET /api/dashboard`
+  - Active events with user's heats
+  - Active matches with partner info, video/rating status
+  - Match requests (incoming + outgoing)
+  - Online count per event (from Socket.IO activeUsers)
+  - Unread count per match (from lastReadAt tracking)
+- [x] ✅ **Database migration** `add_match_last_read_timestamps`
+  - Added `user1LastReadAt`, `user2LastReadAt` to Match model
+- [x] ✅ **Socket.IO enhancements**
+  - `getEventsOnlineCounts()` export for real-time online tracking
+  - Auto-update `lastReadAt` when joining match room
+  - Improved heartbeat (pingInterval: 25s, pingTimeout: 60s)
+  - Infinite reconnection attempts
+
+### Frontend Implementation
+- [x] ✅ **DashboardPage.jsx** - Main dashboard with 3 sections
+- [x] ✅ **EventCard component** - Event info, heats, participants, online count
+- [x] ✅ **MatchCard component** - Partner info, video/rating status, unread badge
+- [x] ✅ **RequestCard components** - Incoming (Accept/Decline) and Outgoing (Cancel)
+- [x] ✅ **VideoExchangeStatus** - Visual indicators (✅ Sent, ✅ Received, ⏳ Waiting)
+- [x] ✅ **RatingStatus** - Visual indicators (You ✓/✗, Partner ✓/✗)
+- [x] ✅ **Skeleton.jsx** - Loading placeholders matching dashboard layout
+- [x] ✅ **Toast notifications** - react-hot-toast for match events
+- [x] ✅ **Rate Partner button** - Shows when video exchange complete, not rated
+
+### Routing & Navigation
+- [x] ✅ Added `/dashboard` route to App.jsx
+- [x] ✅ Changed default redirect after login from `/events` to `/dashboard`
+- [x] ✅ Added Dashboard link to Navbar (desktop + mobile)
+- [x] ✅ Events link added to Navbar
+
+### Real-time Features
+- [x] ✅ Socket.IO listeners for `match_request_received`, `match_accepted`
+- [x] ✅ Toast notifications on match events
+- [x] ✅ Auto-refresh dashboard data on events
+- [x] ✅ Improved socket stability (infinite reconnect, auto-rejoin rooms)
+
+### Tests
+- [x] ✅ **Backend:** 12 dashboard tests passing (dashboard.test.js)
+- [x] ✅ **Frontend:** 19 DashboardPage tests passing (DashboardPage.test.jsx)
+  - Loading skeleton state
+  - Empty states (no events, no matches)
+  - Event card display with online count
+  - Match card display with unread count
+  - Rate button visibility logic
+  - Match request accept/decline actions
+
+### Git Commits
+1. `feat(backend): implement dashboard API endpoint`
+2. `feat(frontend): implement DashboardPage with all sections`
+3. `feat(frontend): add Rate button to MatchCard`
+4. `feat(frontend): add toast notifications for match events`
+5. `feat(frontend): add skeleton loading state for dashboard`
+6. `feat(dashboard): add online count for events`
+7. `feat(dashboard): add unread count for match chats`
+8. `fix(socket): improve connection stability with heartbeat and auto-reconnect`
+
+### Key Features Implemented
+| Feature | Status | Description |
+|---------|--------|-------------|
+| Active Events | ✅ | Event cards with heats, participants, online count |
+| Active Matches | ✅ | Partner info, video/rating status, unread badge |
+| Match Requests | ✅ | Incoming (Accept/Decline), Outgoing (Cancel) |
+| Online Count | ✅ | Real-time users in event chat (green dot) |
+| Unread Count | ✅ | Badge on match avatar (1-9, 9+) |
+| Toast Notifications | ✅ | Dark theme toasts for match events |
+| Loading Skeletons | ✅ | Animated placeholders during load |
+| Rate Partner Button | ✅ | Shows when video exchange complete |
+| Socket Stability | ✅ | Heartbeat, infinite reconnect, auto-rejoin |
+
+### Remaining (Optional Phase 2)
+- ⏳ Activity Feed (timeline of all user activities)
+- ⏳ Smart sort order (unread first, pending ratings, recent activity)
+- ⏳ Dashboard-specific `dashboard_update` socket event
+
+---
+
+**Last Updated:** 2025-11-21 (Dashboard implementation completed)
 **Note:** This file is an archive of completed phases. For current status, see SESSION_CONTEXT.md or TODO.md
 
 **MVP Status:** ✅ 100% Complete - All core features implemented, tested, and production-ready