v2.1.0 - Phase 1 Security Hardening

Release v2.1.0: Phase 1 Security Hardening Complete

- JWT Authentication & Rate Limiting
- Database RLS + Audit Logging
- Structured JSON Logging
- Container Resource Limits
- Non-root Execution (Phase 2 pending)
- Graceful Shutdown & Production Config
- Full Docker Deployment (6/6 services healthy)
- All 12 security controls verified and deployed