Diagnose local x-builder setup and runtime failures. Use when Codex needs to check build artifacts, Node/pnpm prerequisites, Chrome CDP availability, local SQLite/storage boundaries, runner/overlay readiness, or explain why the x-builder overlay, engine, archive import, capture, or feedback loop is not working.
Operate and explain the local x-builder system. Use when Codex needs to run the overlay runner, attach to Chrome over CDP, inspect local engine/storage state, explain archive import, active context, feedback-loop linking, live capture, or safety boundaries in the x-builder repo.