openai/gpt-chat-latest → B (9:1)

Side B makes a substantive architectural change to vote handling: it replaces incremental edge merges with per-actor `uuid_votes` deduplication, introduces pseudonym-to-UUID resolution and seeding, updates event/schema versions, and rebuilds rankings from stored deduplicated votes, with corresponding validation and regression tests. Side A is primarily a consolidation/refactoring that moves room-route helpers into `paths.rs`, relocates tests, and deletes a module without materially changing behavior.