openai/gpt-chat-latest → B (2:1)

Side B fixes a substantive concurrency issue by ensuring `RwLock` read guards are dropped before nested lock acquisition in `RoomCreate` and `RoomGrant`, preventing potential deadlocks, and adds a regression test for private room creation. Side A implements a useful user-facing feature (copying garden rankings as markdown with new UI actions, rendering, and tests), but it primarily adds functionality rather than resolving a core correctness problem.