P1-hat Galerkin discretization of the Weil-form operator A_a (Friedrichs ext of D*G_aD, mean-zero constraint); Toeplitz stiffness via exact piecewise Gauss-Legendre quadrature of g; bottom 12 eigenvalues; absolute validation vs zero-side explicit formula
bottom eigenvalue lambda_a is POSITIVE but very small (~1e-6 scale at a<=5) — earlier table-quadrature version showed spurious -1e-4 values from 1e-3-mesh interpolation noise amplified by 1/h^2; fixed by exact quadrature
eigenvalues of A_a are NOT the zero ordinates: the zeta-aligned operator is Dbar_{a,theta} (first-order, in the T_a-inner-product space) — its spectrum = zeros of W(a,theta;z) (eq 1.11), a separate computation (E-010 candidate)
mean-zero constraint enforced (theorem's operator is on L^2_0)