crates/mcp (L5, engine only): JSON-RPC 2.0 over stdio with protocol version negotiation, a
headless Session backend and a bridge to the app's control port, 14 tools (list_commands,
execute, batch with rollback, inspect_design, measure, body_topology, set_parameter,
screenshot as an image block, export, undo/redo, new_design/open/save) and tests.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL
