~x-ai/grok-latest → B (3:2)

B’s lasting impact is the domain split of room (permission boundary) vs thread_tag (forum channel), the RoomCreated/grants model, and collapsing the REST surface into a single batch RPC that the CLI and tests now use—core spine changes, not mere polish. A is a strong, finished auth design (UUID-canonical identity, Reddit link flow, private linked-providers UX, pending-weight batch fix), but it is additive around accounts rather than reshaping the product’s primary API and event model; B still edges it despite “first pass” migration bulk.