openai/gpt-chat-latest → B (5:1)

Side B is a substantial architectural refactor that consolidates many REST endpoints into a typed RPC interface (`/api/v0/rpc`), updates the CLI to use it, introduces room-scoped data and events (`room_id`/`thread_tag`), and adapts reducers, routing, tests, and shared types to the new model. Side A adds useful UI improvements (vote counts on compare links, HUD unpin action, tests, and styling), but these are incremental features compared with the lasting API and data-model redesign in Side B.