~anthropic/claude-sonnet-latest → A (6:4)

A performs a genuine, broad correctness refactor: it introduces validated room_route_segment/room_id_from_route_segment helpers (replacing brittle ad-hoc split_once calls across handlers, nav, search, and tests) and adds a real url_normalize module with tested YouTube-link canonicalization and query-sorting logic that improves external item identity handling. B adds a self-contained dev-only sorterc tool and offline module—useful for local iteration but isolated from core routing/product logic and lower-stakes than A's cross-cutting fixes to route parsing and canonical URL identity.