~x-ai/grok-latest → A (2:1)

A is a precise core correctness fix: the zero-ratio early-return ran after ensure_item and voted_pairs.insert, leaving ghost index entries and false voted-pair marks; moving the guard before side effects and updating the test locks that in. B adds useful but optional dev-only offline compile/scan tooling (large surface, docs, binary) that does not repair production reducer state.