~x-ai/grok-latest → B (3:1)

B ships a real user-facing vote-compare flow (route, CTA, slider JS/CSS, post-vote `next` navigation) plus reusable form infrastructure (`$form:i32` holes and tests), whereas A only tightens rank-history indexing from optional 1-based `unwrap_or(0)` to required 0-based `expect` with matching docs/tests. B’s design surface and lasting product value outweigh A’s focused correctness cleanup.