Changes:
- Add ssz.zig library dependency from blockblaz/ssz.zig
- Update lean_api.zig to parse SSZ-encoded BeamState from /lean/states/finalized
- Extract slot directly from bytes 8-15 (second field in BeamState after genesis_time)
- Remove fallback to JSON parsing (endpoint returns pure SSZ binary)
- Add upstreams-zeam-only.json for testing with zeam client only

Note: Currently only zeam client implements /lean/states/finalized endpoint correctly.
Other clients (ream, qlean, lantern, etc.) return metrics or error messages instead.

Replace BeamState with LeanState and BeamBlockHeader with LeanBlockHeader
to align with Lean Ethereum naming conventions.

Changes:
- Update /health to /v0/health
- Update /lean/states/finalized to /lean/v0/states/finalized
- Update /lean/states/justified to /lean/v0/states/justified

These endpoints will work once remote lean node images are updated.

Adds a complete web interface inspired by checkpointz for monitoring
leanpoint checkpoint sync status and upstream lean nodes.

Backend changes:
- Add /api/upstreams endpoint to expose detailed upstream status
- Add static file serving for web-dist/ frontend assets
- Add UpstreamsData structures for API serialization
- Add mutex to UpstreamManager for thread-safe access
- Update AppState to reference UpstreamManager

Frontend additions:
- React + TypeScript + Vite setup in web/ directory
- StatusCard component for overall checkpoint status
- UpstreamsTable component for per-upstream monitoring
- CSS theming matching checkpointz aesthetic
- API client for backend communication

Build system:
- Add Makefile with unified build targets
- Support for development workflow (make dev)
- Clean separation of backend/frontend builds

Documentation:
- Add MONOREPO_GUIDE.md with comprehensive usage guide
- Add web/README.md for frontend development
- Update .gitignore for frontend artifacts

Updates Dockerfile to build and ship the React web UI alongside the
Zig backend. The Docker image now includes a complete monorepo deployment.

Changes:
- Add Node.js to build stage for frontend compilation
- Build web UI during Docker image creation
- Copy web-dist/ to /usr/share/leanpoint/web/ in runtime image
- Update default CMD to serve web UI automatically
- Update MONOREPO_GUIDE.md with corrected Docker instructions

The Docker image now provides a complete web interface out of the box.
Access the UI at http://localhost:5555 when running the container.

Merges all monorepo documentation into the main README for a single
source of truth. The README now covers both backend and frontend with
updated quick start, development workflow, and deployment instructions.

Runs zig fmt on all source files to fix formatting issues.
Adds .eslintrc.cjs for frontend linting with TypeScript and React rules.

Removes upstreams-*.json files from git tracking, keeping only
upstreams.example.json as a template. User-specific configs should
be generated locally and are now properly ignored.

Updates .gitignore to exclude all upstreams-*.json except the example.