~x-ai/grok-latest → A (3:1)

A upgrades core pair-selection with lasting design (established-component attach before isolate pairs; rank-centrality zip once connected) plus several targeted tests, shaping how rankings grow day-to-day. B is a real correctness fix (move zero-ratio return before ensure_item/voted_pairs) but a narrow edge-case guard with small scope versus A’s behavioral impact.