feat(mcp): local MCP server — scan_repo + blueprint_scene (proof)

[New1Direction]

Summary

A new mcp/ package: a local stdio MCP server exposing RepoLens's analysis as tools, so an LLM client (Claude Desktop/Cursor) can call them and render the structured JSON as components (the Generative-UI loop). Stays true to the no-backend stance — runs locally, key from ANTHROPIC_API_KEY, nothing phones home.

Tools

• scan_repo({ repo }) — verdict-first analysis (fit/health/pros/cons/red_flags/capabilities).
• blueprint_scene({ repo }) — laid-out nodes/edges graph (for a <DependencyGraph>), via the deep-dive atoms+lineage pipeline.

Design

• Reuses the extension's own modules verbatim (fetcher.js, prompt.js, parser.js, deepdive.js, blueprint-adapter.js) — single-source engine, no fork. Only the env-key Anthropic call (mcp/anthropic.js) is MCP-specific.
• Isolated package (mcp/package.json + @modelcontextprotocol/sdk), so the extension stays zero-dep.

Test plan

• Unit: parseRepoInput (owner/name, URL, .git, errors) — 6 tests; full repo suite 849 green; eslint clean
• npm install clean (0 vulns); MCP handshake advertises both tools with schemas (smoke pass)
• Live: ANTHROPIC_API_KEY=... node mcp/server.js, call scan_repo/blueprint_scene from a client against a real repo (needs key + network)

Notes

• First deps-bearing subpackage in the repo (unavoidable for an MCP server); kept isolated under mcp/.
• Follow-ups: deep_dive, multi-provider, npm/PyPI/GitLab, GITHUB_TOKEN pass-through.