docs: update TODO and COMPLETED with spam protection and notifications

- Mark S15.1-15.2 (Rate Limiting & Spam Protection) as implemented
- Mark S16.1 (Socket Notifications) as implemented
- Update test count: 342 → 350 tests
- Add implementation details to COMPLETED.md
- Update recent work timeline

docs/TODO.md

@@ -7,8 +7,10 @@
 ## Current Status
 
 **Phase:** MVP Complete - Production Ready
-**Tests:** 342/342 passing - 100% ✅ (72.5% coverage)
-**Recent Work:** Matching runs audit, ratings & stats system, comprehensive test suite completed (2025-11-30)
+**Tests:** 350/350 passing - 100% ✅ (73% coverage)
+**Recent Work:**
+- 2025-11-30: Matching runs audit, ratings & stats system, comprehensive test suite
+- 2025-11-30: Rate limiting & spam protection, socket notifications for suggestions
 
 **Full implementation history:** See `docs/archive/COMPLETED.md`
 
@@ -28,6 +30,10 @@
 - **S11.3-11.4:** Matching Run Details API - Admin endpoints with filtering
 - **S12:** Multi-heat collision detection - Covered in matching algorithm tests
 - **S14.1:** Only recorder can accept/reject - Implemented in MVP
+- **S15.1-15.2:** Rate Limiting & Spam Protection - 8 comprehensive tests
+  - Max 20 pending outgoing match requests
+  - Rate limit: 10 match requests per minute
+- **S16.1:** Socket Notifications - Real-time notification when new suggestion created
 - **Matching Runs Audit:** 6 comprehensive tests (origin_run_id tracking)
 
 #### 🔴 Critical Gaps (P0 - Before Production)
@@ -46,13 +52,6 @@
    - Current: Manual blocks only NEW auto suggestions, old pending remain
    - Need: Cleanup conflicting pending auto suggestions when manual match created
 
-4. **S15.1-15.2: Rate Limiting & Spam Protection**
-   - Max pending outgoing requests (20)
-   - Rate limit manual match requests (10/minute)
-
-5. **S16.1: Socket Notifications**
-   - Real-time notification when new suggestion created
-
 #### 📋 Medium Priority (P2 - Q1 2025)
 
 6. **S15.3: Zombie Matches Cleanup**