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

A consolidates duplicated room-id/slug splitting logic into a single `room_route_segment`/`room_id_from_route_segment` API (used consistently across UI, API, and tests) and adds a well-tested external-URL normalization module (YouTube canonicalization, query sorting) that improves identity correctness for garden items—substantial, tested infrastructure work. B is a narrower but solid correctness fix (rejecting invalid vote ratios) with good test coverage, but it's much smaller in scope and impact compared to A's broader refactor and new normalization capability.