~anthropic/claude-sonnet-latest → A (6:4)

Side A fixes an actual correctness bug in vote-outcome highlighting (winner/slider mapping, polarity), adds solid regression tests (`ratios_for_page_orients_to_page_left`, `sliding_left_makes_left_item_win_ranking`) verifying the invariant end-to-end, and improves CSS/JS to correctly reflect the winner state including a previously-missing 'even' case. Side B is a good but purely cosmetic enhancement (score-based gradient instead of position-based) without fixing any functional bug, making A's contribution more consequential to correctness even though it also carries some unrelated refactor noise.