openai/gpt-chat-latest → B (3:2)

Side B introduces reusable infrastructure by centralizing private-room route encoding/decoding (`room_route_segment`, `room_id_from_route_segment`, `ROOM_SHORT_ID_LEN`) and updating routing, URL generation, and tests to use it consistently, while also improving URL canonicalization for external identities (including YouTube normalization and query normalization). Side A makes a sweeping DSL syntax change requiring vote explanations to precede comparisons and updates the parser, UI, documentation, and many fixtures, but much of the patch is mechanical migration to a new syntax rather than adding broadly reusable functionality.