\section{Exact checks and audit scope}\label{app:checks} \subsection{The identities and endpoint certificates} The finite checks compare the proof's formulas with separate exact calculations. They supplement the arguments for arbitrary parameters; the proof does not extrapolate from the checked cases. For example, Gram entries can be calculated either from partial fractions or from moments of the positive weight. With each $\alpha=v/d$ reduced, put \[ \Delta=\prod_{v/d\in\Lambda}d^2,\qquad P_*(x)=\prod_{v/d\in\Lambda\setminus\mathcal A}(d^2x+v^2). \] Then \[ \frac{\prod_{\alpha\in\Lambda}(x+\alpha^2)}{Q(x)} =\frac{P_*(x)}{\Delta}. \] The elementary beta integral gives, for $0\le j