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

Side A introduces the core pairwise-voting infrastructure (pair.rs bridge-selection algorithm with tests, vote.rs compare page, morph-based vote recording) plus a real correctness fix (ItemId::from_storage normalizing reddit permalink slugs) and adds test coverage/refactors test support code. Side B is a narrower, later fix-up (attribution placement, removing a fallback bug, dropping a UI button, route rename) that is useful but smaller in scope and builds on infrastructure like A's rather than creating it.