~x-ai/grok-latest → A (3:2)

Commit A delivers a real end-to-end capability: entity fetch becomes an SSE stream with fetching/complete/error events, oneshot FetchJobResult completion from the Reddit worker, a dedicated fetch module, and matching JS/client plus integration-test updates. Commit B is valuable lasting design (drop room visibility, rooms as a HashSet, wire CLI `room create` and docs), but it mostly simplifies an existing RoomCreate path rather than adding comparable multi-layer product behavior.