openai/gpt-chat-latest → A (4:3)

Side A performs a broad but coherent refactor that centralizes room URL encoding/decoding into shared helpers (`room_route_segment`, `room_id_from_route_segment`, `ROOM_SHORT_ID_LEN`), updates routing and link generation consistently across the server, and adds URL normalization logic with tests, reducing duplicated parsing and making URL handling more maintainable. Side B adds a substantial Reddit background fetch pipeline with OAuth, rate limiting, and parsing, but it is a new feature with placeholders still remaining (for example the TODO file and no rendering changes), making its long-term project impact less certain than A's foundational cleanup and normalization.