Scale Graphs V: Matrix Scale Graphs and Multi-Edge Closure for Dissipative RG

This is the fifth paper in the Scale Graphs sequence. The first paper proved a strict scalar Lyapunov identity for minimum-production renormalization; the fourth paper showed that two scalar production-selection gates fail on archived Navier-Stokes scale data. The present paper moves the theory to the multichannel setting in which the strong bridge naturally lives. The mathematical core is a matrix Onsager production law P_i(lambda) = lambda^T A_i lambda - 2 J_i^T lambda + Y_i, with A_i symmetric positive definite, Prigogine coordinates p_i = A_i^{-1} J_i and kappa_i = Y_i - J_i^T A_i^{-1} J_i >= 0. We prove the matrix series law A_eff = (A_1^{-1} + A_2^{-1})^{-1}, p_eff = p_1 + p_2, kappa_eff = kappa_1 + kappa_2, and, more importantly, the matrix analogue of the strict Lyapunov identity: P_1 + P_2 - P_eff = (q_1 - q_2)^T (A_1 + A_2)^{-1} (q_1 - q_2) >= 0. Equality holds exactly at matrix Prigogine closure. We then lift the cell identity to a finite matrix scale graph: eliminating all internal vertices by a Schur complement gives a global matrix Lyapunov identity, with the production drop equal to a positive semidefinite quadratic form in the eliminated harmonic residuals. Thus the Lyapunov mechanism of the scalar theory is not a path-graph accident; it survives in the multichannel theory. We also record the operator structure of the matrix series law. The parallel sum is monotone in the Loewner order, so ellipticity windows and spectral brackets are stable under matrix decimation. We also prove an ellipticity-preservation theorem: if mI