Phase 3 synthesizing SR-discovered H(z) and RAR forms into empirical discriminants for DM models. We present a GP hook null test (3/164 significant — consistent with null), mass-weighted EFE analysis (null result across 3 proxies), abundance-matched MCMC ((\sigma_8 = 0.900), (\Omega_m = 0.246)), MaNGA cross-validation (10,052 independent galaxies), SPARC sub-sample cross-validation (CPX5 parameters are range-dependent at 15(\sigma)), and a systematic-error-aware forecast for Euclid/Rubin/Roman. Adversarially validated over 4 debate rounds (24 challenges, 0 fatal).