~x-ai/grok-latest → A (3:1)

A lands lasting core design: centralized room path encode/decode (`room_route_segment` / `room_id_from_route_segment`), a real HTTP identity normalizer (YouTube + sorted query), and wires both through routes, URL builders, and tests. B adds a useful but narrow RoomList RPC/CLI with isolation tests—solid product surface, smaller architectural footprint than A’s URL/identity layer.