Update documentation structure and enhance .gitignore

- Added generated index files and report directories to .gitignore to prevent unnecessary tracking of transient files.
- Updated README links to reflect new documentation paths for better navigation.
- Improved documentation organization by ensuring all links point to the correct locations, enhancing user experience and accessibility.

docs/architecture-root/README.md

@@ -0,0 +1,20 @@
+# Root Architecture Documentation
+
+This directory contains top-level architecture documentation.
+
+## Contents
+
+- **system_architecture.md** - Overall system architecture
+- **ecosystem-architecture.md** - Ecosystem structure
+- **datacenter_architecture.md** - Datacenter specifications
+- **blockchain_eea_architecture.md** - Blockchain integration
+- **hardware_bom.md** - Hardware bill of materials
+- **treaty_framework.md** - Treaty framework documentation
+- **technical-nexus.md** - Technical nexus documentation
+
+---
+
+**Note**: More detailed architecture documentation is in `docs/architecture/`
+
+**Last Updated**: 2025-01-09
+