~x-ai/grok-latest → A (2:1)

A fixes lasting vote-UI correctness (center-anchored winner fill, ratio/slider polarity, history bars aligned with the HUD) plus per-group gradient scoping and adds polarity/ranking invariant tests. B is a real design upgrade—score min–max coloring instead of list ordinals—but it is a narrower visualization tweak that builds on the same rank_row path without the multi-surface bugfixes and core tests in A.