openai/gpt-chat-latest → A (5:2)

Side A introduces a substantive URL-routing refactor by centralizing private room path encoding/decoding (`room_route_segment`/`room_id_from_route_segment`), replacing ad hoc string splitting across handlers, routes, navigation, URL builders, and tests. It also adds reusable URL normalization utilities (including canonicalization for external URLs such as YouTube links), improving long-term consistency and maintainability, whereas Side B mainly fixes vote-page behavior, removes an unnecessary UI control, renames `/vote/compare` to `/vote`, and corrects delegate handling for vote posts.