Why: Ruling 5's final item. With the user-provided lmuai endpoint
(claude-opus-5-5) and the P5 build unchanged, the same golden task set ran
both sides to completion (6/6 turns each).
Evidence: SELF - B report .task/model-ab/ab-opus.json (2793s) vs A baseline
.task/phase05-eval/after-p5.json; smoke through the live instance confirmed
the provider switch (after fixing the active-secret shadowing: overlayKey
prefers the secret table, so provider changes need /api/secrets rotation).
Impact: Selection report in the card - opus-5-5 eliminates invented numbers
(7 -> 0, the program's core metric), restores independent verification via
lightweight=deepseek-v4-flash; MiniMax stays as the fast/fallback tier.
Recommended default documented for the owner.