~x-ai/grok-latest → A (2:1)

A introduces a durable browse URL model (`ItemId::browse_href` / `from_browse_uri`, `/~/*` routing) and removes the theme cookie/CSS stack with matching integration tests, which changes how the app is navigated long-term. B is a worthwhile type-safety refactor (Deref on href newtypes, `resolve_item` → `CanonicalItemUrl`, fewer String re-wraps) but is mostly internal plumbing without new behavior or user-facing design.