Add FastAPI registry server that pre-fetches all component data from
hanzoai/ui on GitHub, caches in memory, refreshes every 15min. Serves
instant cached responses. Deploy at ui.hanzo.ai.
- registry/cache.py: eager full-cache with concurrent GitHub fetching
- registry/server.py: FastAPI endpoints for components, blocks, search
- registry/client.py: RegistryClient matching GitHubAPIClient interface
- Dockerfile for containerized deployment
- UiTool now uses 3-tier fallback: local disk → registry → GitHub API
- Bump hanzo-tools-ui to 0.2.0, server deps optional (fastapi, uvicorn)