Review vote rollback overwrites votes on other reviews #799

Found in a post-merge review of #792 (#790).

handleVote in apps/web/src/components/reviews/JReviewsSection.tsx snapshots the whole userVotes map (votesBefore = userVotes) and restores it on a refused vote. pendingIds only locks the clicked review, so a reader can vote on review B while A's request is in flight. The last rollback to run writes back a stale copy of the whole map to state and rate_review_votes_v1:

• A and B both refused (403/429): A's refused vote is re-highlighted and stored although its count was rolled back; A's next click sends clear.
• A refused, B accepted, A's response last: B's saved vote is wiped locally; B's next click sends up again.

The optimistic update (updatedVotes = { ...userVotes }) builds from the same render-time copy.

Fix: roll back and apply only the clicked review's entry with functional state updates.

Acceptance: an E2E test that votes on two reviews while the first request is pending, refuses both, and expects neither to stay highlighted or stored; the existing rollback spec stays green.