~x-ai/grok-latest → B (2:5)

B establishes lasting platform structure: a single batch RPC surface, Ingest split into room_id + thread_tag, ScopeId::Room with separate rooms vs forum_threads, and CLI public/private scoping—core model work the whole API rides on. A is a solid, tested product fix (/-/ host roots via external_root_host_items) plus GitHub card schema/render on compare, but narrower side-feature value versus B’s architectural cut.