Update documentation with last updated dates and improve navigation indexes

- Added "Last Updated" date to multiple documentation files for better tracking.
- Enhanced the README with quick navigation indexes for guides, references, and architecture documentation.
- Updated titles in Keycloak deployment and testing guide for consistency.

docs/README.md

@@ -99,9 +99,17 @@ Historical documentation is archived in [docs/archive/](./archive/) for referenc
 - [Build Results](./archive/builds/) - Historical build results
 - [Deployment Reports](./archive/deployments/) - Historical deployment reports
 
+## Documentation Indexes
+
+Quick navigation to specific documentation types:
+- **[Guides Index](./GUIDES_INDEX.md)** - All how-to guides and tutorials
+- **[Reference Index](./REFERENCE_INDEX.md)** - API docs, specs, and reference material
+- **[Architecture Index](./ARCHITECTURE_INDEX.md)** - Architecture and design documentation
+
 ## Documentation Maintenance
 
 For documentation improvements and audits, see:
 - **[Documentation Deep-Dive Analysis](./DOCUMENTATION_DEEP_DIVE_ANALYSIS.md)** - Comprehensive documentation analysis
+- **[Documentation Fixes Applied](./DOCUMENTATION_FIXES_APPLIED.md)** - Recent documentation improvements
 - **[Audit Summary](./AUDIT_SUMMARY.md)** - Quick audit reference