docs: update documentation with Activity Log System implementation

Updated all major documentation files to reflect the completed Activity
Log System (Phase 3.5) implementation.

Changes:
- README.md: Added Admin & Monitoring section, updated database schema
  to 12 tables, added Activity Log System to completed phases, updated
  project structure to show admin pages and services
- SESSION_CONTEXT.md: Updated recent work, added activity log system to
  core features, updated database schema, added comprehensive Phase 3.5
  overview with all implementation details
- COMPLETED.md: Added full Activity Log System entry with all 8 phases,
  implementation details, git commits, and access information

Updated dates to 2025-12-02.

docs/SESSION_CONTEXT.md

@@ -17,7 +17,7 @@
 
 **Phase:** MVP Complete - Production Ready
 **Tests:** 342/342 backend tests passing - 100% ✅ (72.5% coverage)
-**Recent Work:** Matching runs audit, ratings & stats system, comprehensive test suite
+**Recent Work:** Activity Log System with real-time admin dashboard (Phase 3.5 complete)
 
 ### Core Features (All Implemented)
 - JWT authentication with email verification (AWS SES)
@@ -37,6 +37,7 @@
 - PWA (offline support, iOS compatible)
 - Security: CSRF, rate limiting, account lockout
 - Test bot for automated testing
+- Activity Log System - admin monitoring dashboard with real-time streaming (18 action types)
 
 ---
 
@@ -47,6 +48,7 @@
 ├── docker-compose.yml       # nginx:8080 + frontend + backend + db
 ├── frontend/src/
 │   ├── pages/               # React pages
+│   │   └── admin/           # Admin pages (ActivityLogsPage.jsx)
 │   ├── components/          # Reusable components
 │   ├── contexts/            # AuthContext
 │   ├── services/            # api.js, socket.js
@@ -55,8 +57,10 @@
 ├── backend/src/
 │   ├── routes/              # API endpoints (events.js, matches.js, admin.js)
 │   ├── controllers/         # Business logic
-│   ├── services/            # matching.js (auto-matching algorithm)
-│   ├── socket/              # Socket.IO handlers
+│   ├── services/            # matching.js (auto-matching), activityLog.js (audit trail)
+│   ├── middleware/          # auth.js, admin.js (requireAdmin)
+│   ├── socket/              # Socket.IO handlers (chat, WebRTC, admin logs)
+│   ├── utils/               # request.js (IP extraction)
 │   ├── constants/           # Status constants
 │   └── __tests__/           # Jest tests (342 tests - 100% passing)
 │       ├── matching-algorithm.test.js      # 19 tests
@@ -77,10 +81,10 @@
 
 ---
 
-## Database Schema (11 tables)
+## Database Schema (12 tables)
 
 Key models:
-- `users` - Auth, profile, social links, location, lockout fields
+- `users` - Auth, profile, social links, location, lockout fields, `isAdmin` flag
   - Account tiers: `accountTier` (BASIC/SUPPORTER/COMFORT), `recordingsDone`, `recordingsReceived`
 - `events` - Dance events with unique slugs
 - `event_participants` - User-event relationship, competitorNumber, recorderOptOut, `accountTierOverride`
@@ -90,33 +94,37 @@ Key models:
 - `recording_suggestions` - Auto-matching results with collision detection, `originRunId` tracking
 - `matching_runs` - Audit trail (manual/scheduler, status, stats)
 - `chat_rooms` / `messages` - Real-time chat persistence
+- `activity_logs` - Comprehensive audit trail (18 action types, indexed for performance)
 
 ---
 
-## Recent Changes (Last 2 Days)
+## Recent Changes (2025-12-02)
 
-### Matching Runs Audit System
-- **File:** `backend/src/__tests__/matching-runs-audit.test.js` (6 tests)
-- **Features:**
-  - origin_run_id assignment and tracking
-  - Sequential runs create separate audit records
-  - Accepted suggestions preserve origin_run_id across re-runs
-  - Admin endpoints with filtering (onlyAssigned, includeNotFound)
-  - Manual vs scheduler trigger differentiation
+### Activity Log System (Phase 3.5) - Complete ✅
+**Comprehensive admin monitoring with real-time streaming dashboard**
 
-### Ratings & Stats Integration
-- **File:** `backend/src/__tests__/ratings-stats-flow.test.js` (9 tests)
-- **Features:**
-  - Atomic stats updates (recordingsDone, recordingsReceived)
-  - Race condition prevention with `statsApplied` flag
-  - Source filtering (only auto matches update stats)
-  - Idempotency (double-rating prevention)
-  - E2E double-rating completion flow
+**Backend (Phases 1-5):**
+- `activity_logs` table with 18 action types (AUTH_*, EVENT_*, MATCH_*, ADMIN_*, CHAT_*)
+- `activityLog.js` service - fire-and-forget logging, never blocks requests
+- `requireAdmin` middleware - fresh DB check for admin status
+- 3 API endpoints: query logs, get action types, get statistics
+- Socket.IO streaming - `admin_activity_logs` room with permission check
+- 14 integration points across auth, events, matches, socket handlers
 
-### Documentation
-- **Updated:** README.md with current test statistics (342/342)
-- **New:** docs/TESTING_MATCHING_RATINGS.md (comprehensive 45-test overview)
-- **Archived:** Outdated quick start guides
+**Frontend (Phases 6-7):**
+- `ActivityLogsPage.jsx` (600+ lines) - full admin dashboard
+- Stats dashboard: total logs, unique users, failures, 24h activity
+- Advanced filtering: date range, category, action type, username, success/failure
+- Paginated table (50 per page) with color-coded action badges
+- Real-time streaming toggle (Socket.IO integration)
+- Admin-only route `/admin/activity-logs` with Shield icon in navbar
+
+**Files Created/Modified:**
+- Backend: `schema.prisma`, `activityLog.js`, `admin.js`, `request.js`, admin routes
+- Frontend: `ActivityLogsPage.jsx`, `api.js`, `App.jsx`, `Navbar.jsx`
+- Integration: 14 logging points in auth, events, matches, socket handlers
+
+**Admin User:** spotlight@radziel.com / Dance123!
 
 ---
 
@@ -221,4 +229,4 @@ REST_BUFFER_MINUTES: 60
 
 ---
 
-**Last Updated:** 2025-11-30
+**Last Updated:** 2025-12-02