openai/gpt-chat-latest → A (4:1)

Side A introduces a substantial, cross-cutting URL and routing refactor: it centralizes room route encoding/decoding with new `room_route_segment`/`room_id_from_route_segment` helpers, updates server routing and URL generation to a unified `/r/{room_key}` format, and adds URL normalization infrastructure (including canonicalization improvements and tests). Side B is a focused validation change that enforces vote ratio bounds across the parser, UI, and reducer with appropriate regression tests, but its impact is narrower than the architectural routing and URL normalization work in Side A.