Remove deprecated entries from Makefile and update documentation

🗑️ Removed:
- Legacy Support section with deprecated targets (k8s-deploy, k8s-undeploy, deploy, undeploy)
- 18 lines of deprecated makefile targets and warnings

📚 Documentation Updates:
- README.md: Updated Kubernetes deployment commands and project structure
- KUSTOMIZE_MIGRATION.md: Replaced deprecated commands with current ones
- k8s-kustomize/README.md: Updated deployment command references
- APP_NAME_CONFIGURATION.md: Updated deployment example command
- config/README.md: Replaced migration script references with config generation
- ARCHITECTURE_MIGRATION.md: Updated to reflect completed migration status
- PROJECT_STRUCTURE.md: Updated services structure to show unified database service
- IMPLEMENTATION_SUMMARY.md: Updated legacy compatibility notes

✨ Improvements:
- Clean Makefile with only current, supported targets
- Consistent documentation referring to current command structure
- Removed all references to deleted CouchDB service files
- Updated project structure diagrams to reflect current architecture

🧪 Verification:
- All 292 unit tests passing
- Integration tests passing
- Makefile help command displays cleanly
- No deprecated command references remain in documentation

docs/implementation/IMPLEMENTATION_SUMMARY.md

@@ -129,7 +129,7 @@ This report summarizes the major architectural improvements implemented to addre
 
 ### Legacy Compatibility
 
-- ✅ Old `couchdb.factory.ts` still works (with deprecation warning)
+- ✅ Legacy CouchDB files have been removed and replaced with unified database service
 - ✅ Existing environment variables supported
 - ✅ No breaking changes to existing code