nx_sdfprim_gate.nx

nx_sdfprim_gate.nx -- KNOWN-ANSWER TEETH FOR THE IMPLICIT PRIMITIVE FAMILY nx_sdfprim_lib (anatomy AN17, 2026-09-19). Every tooth is a distance a hand can check: a sphere is where the first-order ellipsoid estimator is EXACT, so its values are asserted to the unit; the walled cylinder and the swept arch are asserted at points that lie on a primitive's own construction (a polyline vertex, an axis crossing) where the answer is closed-form. The pitched ellipsoid is held to the plain one at zero tilt (an identity) and to the axis swap at a quarter turn. NEG-CONTROL: the detector "a point off the surface reads non-zero" must fire on a planted 5 mm shift and stay silent on the surface point (gv_bite): a primitive that read zero everywhere would pass every equality tooth by accident. license_tier: ORIGINAL. No hw writes (Rule 26).