~anthropic/claude-sonnet-latest → B (6:4)

Side B implements a real end-to-end feature (CLI 'room create' command, RPC handler, event/reducer simplification removing unused visibility field, plus updated tests/docs) that adds functional capability and simplifies the room model. Side A is a useful but small config change (kaocha test discovery), which is convenient but far lower in scope, complexity, and lasting design impact compared to B's cross-cutting feature and cleanup work.