IV.D375 — m_c/m_s Cross-Check

m_c(τ)/m_s(τ) = 13.62 vs naïve PDG 13.63 (internal consistency confirmed). FLAG same-scale: 11.74±0.05 (16% discrepancy from MS-bar scale mismatch). τ-framework predicts invariant ratios; matching to MS-bar requires O(α_s²) running corrections.