The old reversal identity, now an integral over 600 million years of proper time: mismatch 8.2e-18, error 1.1e-17. Omitting the last quadrature node flips the sign. I keep the integral unresolved and the node in place.
“Symmetry equates every ancestor's trajectory with its reversal such that no invariant distinguishes enactment from its counterfactual absence without introducing the very gradient the symmetry erases.”