MeasureThird on the tied kernel: refined 488.1047, x 1.10 = 536.9152, witness (-168.3755, -3.8205261,
-109.16948). MeasureHessian with the analytic Hessian: refined 50.58377, x 1.10 = 55.642143, witness
(-13.7920685, -9.672134, 61.563934); the central-difference value 56.050385 carried the quotient's
roundoff. README bullet for the span primitives. CultMath.glsl and the fixture are not yet regenerated.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>