Pure Mean-Law Collapse and One-Bit Veto Rescue of a Masked-Veto Quartet Class in a Computational Longevity Discovery Pipeline (Trinity Claims #69-#73, 2026-03-20)

This version fixes the first constructive repair for the Trinity masked-veto structural blind spot. Claims #69-#73 establish avg-pair versus veto aliasing inside quartet-space, a masked-veto quartet class with zero retention in standard top-k universes, the absence of a native fracture channel in the candidate law, exact pure-mean-law equivalence of full-support quartet ranking, and a minimal one-bit veto rescue rule in which prepending weak_flag before the existing mean order restores all 25 masked-veto quartets into the top-25 and lifts the target fracture quartet to rank 21. The package contains the structural blind-spot freeze, the rescue freeze, the supporting phase reports and summaries, and concise translational descriptions. This is a computational discovery package and not a completed causal validation study.