openai/gpt-chat-latest → A (5:1)

Side A implements substantial new functionality: browser session cookies and login/logout flow, web posting, room-aware forum pages and routing, shared authentication via cookies or bearer tokens, and the necessary API/router integration to make the room UI work again. Although it also includes a large non-functional planning document, the code changes add enduring capabilities, whereas Side B is a focused correctness fix that moves the zero-ratio guard before `ensure_item`/`voted_pairs.insert` to prevent ghost items and invalid voted pairs, with an updated regression test.