nx_security_census_gate.nx

nx_security_census_gate.nx -- regression-by-construction for the security census's MEASURED CORE. Proves the three load-bearing behaviours without needing the whole catalog live: (1) coverage permille math (incl. the div-by-zero guard), (2) WEAKEST-LINK weighting -- criticals (weight 3) dominate, so a count-majority of standard controls cannot mask a missing critical one, (3) the disk oracle BOTH WAYS -- a known-present organ reads HAVE, a known-GAP organ (the W4 target, which must stay absent) reads GAP -- the same no-fabrication discipline as the seed-gate neg-control. license_tier: ORIGINAL