~x-ai/grok-latest → B (2:3)

B adds a core product RPC (RoomList) plus CLI and integration tests that lock in per-principal grant isolation—lasting API surface the app needs. A is strong offline DX (fast parse-only scan, richer parse_error, compile --ingest) but remains tooling around logs rather than new user-facing capability; B’s value is thinner code-wise but more central and durable for the system.