Add all documentation subdirectories to the curated markdown linting targets, replacing the previous exclusion-based approach with comprehensive coverage. Update validation to check for required README files across all hubs and verify priority documentation metadata markers. Implement lazy loading for optional dependencies (numpy, redis, bcrypt, jwt, websockets) in agent-coordinator and related modules to improve startup
- Relocate blockchain-event-bridge README content to docs/apps/blockchain/blockchain-event-bridge.md
- Relocate blockchain-explorer README content to docs/apps/blockchain/blockchain-explorer.md
- Replace app READMEs with redirect notices pointing to new documentation location
- Consolidate documentation in central docs/ directory for better organization