~anthropic/claude-sonnet-latest → B (7:3)

Side B delivers a real user-facing feature (account/alias management page, alias switching, re-linking OAuth) with corresponding CSS, template, and test updates, representing lasting functional value. Side A is a solid but narrow internal refactor (Rc<RefCell> -> plain HashMap + OnceLock singleton) that improves code quality and enables Send+Sync but has much smaller scope and impact than B's feature work.