docs: finalize CLAUDE.md with completed authentication system status

- Updated project documentation to reflect completed Phase 4 authentication work
- Added comprehensive authentication system completion status (items 36-43)
- Documented MFA, RBAC, session management, and organization features
- Sprint preparation complete for tomorrow's team start

🎯 All authentication tasks (4.5-4.8) successfully completed and documented
🚀 Project ready for next development phase

Author: ScientiaCapital

CLAUDE.md

@@ -344,6 +344,16 @@ Remember: With great MCP power comes great productivity! Use the right tool for
 34. **✅ Cost Estimation** - Real-time pricing with model-specific optimization
 35. **✅ Organization Models** - SwaggyStacks (gaming) + Scientia Capital (enterprise) configs
 
+### **LATEST: Enterprise Authentication System Complete** ✅ (Sept 20, 2025 Evening)
+36. **✅ Multi-Factor Authentication (MFA)** - TOTP with QR code enrollment and recovery flows
+37. **✅ Role-Based Access Control (RBAC)** - 4-tier hierarchy with 15+ granular permissions
+38. **✅ Session Management** - Auto-refresh, cross-tab sync, health monitoring with metrics
+39. **✅ Organization Management** - Multi-tenant architecture with role inheritance
+40. **✅ Enhanced AuthContext** - Unified state management across all auth features
+41. **✅ TypeScript Integration** - Full type safety for all authentication components
+42. **✅ UI Component Suite** - Complete admin interfaces for all auth features
+43. **✅ React Hook Library** - Intuitive APIs for session, RBAC, and organization management
+
 ### Key Infrastructure Files
 
 #### Phase 3.5 Production Systems