openai/gpt-chat-latest → A (3:2)

Side A introduces a substantial architectural improvement by moving vote recording into a dedicated settlement worker that batches event-log writes, recomputes cached rankings asynchronously, adds cached ranking reads, and switches UI paths from write locks to read locks. It also removes the temporary demo counter feature and simplifies the main UI, whereas Side B mainly adds a new vote-comparison UI flow, pair-selection logic, and ID normalization, which are valuable features but less foundational than the concurrency and caching changes in Side A.