~anthropic/claude-sonnet-latest → B (60:40)

Side B untangles a real design flaw—rooms (permission boundary) were previously conflated with forum threads—introducing a proper `RoomCreated`/`RoomState` model and a unified RPC batch API that the CLI and tests are migrated onto, which is a more foundational and consequential architecture fix. Side A is a solid but narrower DRY refactor (a shared `room_route_segment` helper plus new URL/YouTube normalization) that removes duplication but also trades away human-readable `/r/{short}/{slug}` URLs for a concatenated, length-coupled segment. Both are substantial, but B addresses a deeper structural problem with broad, well-tested follow-through, giving it more lasting value despite being messier and self-described as a first pass.