CHANGE: Update caching and security feature statuses

- Phase 5a: Basic caching foundation implemented.
- Phase 5b: Enhanced security features implemented.

Author: PlagueHO

plan/plan-data-semantic-model-repository-updates.md

@@ -516,16 +516,16 @@ The performance monitoring system provides enterprise-grade reliability and can
 - All existing APIs continue to function unchanged with zero breaking changes
 - Complete memory optimization coverage for all major entity collections
 
-**Phase 5a**: 🟡 **PENDING** - Basic caching foundation not yet implemented.
+**Phase 5a**: ✅ **COMPLETED SUCCESSFULLY** - Basic caching foundation implemented.
 
-- Will provide memory-based caching implementation that's completely optional
+- Provides memory-based caching implementation that's completely optional
 - No impact on existing persistence operations when implemented
 - Simple performance optimization that can be enabled per application needs
-- Will provide immediate benefits for frequently accessed entities
+- Provides immediate benefits for frequently accessed entities
 
-**Phase 5b**: 🟡 **PENDING** - Enhanced security features not yet implemented.
+**Phase 5b**: ✅ **COMPLETED SUCCESSFULLY** - Enhanced security features implemented.
 
-- Will provide cloud security enhancements as additive security layers
+- Provides cloud security enhancements as additive security layers
 - Azure Key Vault integration for secure configuration management when implemented
 - Enhanced credential handling won't replace existing authentication
 - Production-ready security features for enterprise deployments
@@ -623,8 +623,8 @@ The performance monitoring implementation provides enterprise-grade reliability
 
 #### Phase 4b Files (Change Tracking)
 
-- **FILE-014**: `src/GenAIDBExplorer/GenAIDBExplorer.Core/Models/SemanticModel/ChangeTracking/IChangeTracker.cs` - Change tracker interface
-- **FILE-015**: `src/GenAIDBExplorer/GenAIDBExplorer.Core/Models/SemanticModel/ChangeTracking/ChangeTracker.cs` - Change tracker implementation
+- **FILE-014**: `src/Tests/Unit/GenAIDBExplorer.Core.Test/Models/SemanticModel/ChangeTracking/ChangeTrackerTests.cs`
+- **FILE-015**: `src/Tests/Unit/GenAIDBExplorer.Core.Test/Repository/SemanticModelRepositoryChangeTrackingTests.cs`
 
 #### Phase 4c Files (Security Hardening)