openai/gpt-chat-latest → A (3:2)

Side A implements a substantial new capability: pool-scoped voting, including `/vote?pool=...` routing, pair selection from a parent's children, preservation of pool context through post-vote navigation, and UI entry points for voting on child items. Side B fixes a real reducer bug by moving the zero-ratio early return before `ensure_item` and `voted_pairs` registration to prevent ghost items and incorrectly marked pairs, but it is a localized correctness fix compared with the broader, integrated functionality added in Side A.