openai/gpt-5.3-chat → A (4:1)

Side A introduces substantial cross-cutting functionality: a full theme system (cookie handling, POST /theme, layout changes) and correct room-aware URL generation by replacing item_path_for_api with item_path_for_api_in_room throughout RPC and helpers. Side B is a focused UI improvement (vote counts, HUD unpin behavior) with a small helper and test, but far less impactful to core behavior.