IV.T191 — Charm Mass from τ-Chain at +1150 ppm

m_c = m_t(τ) × ι_τ^(105/23) = 172440 × 0.007391 = 1274.5 MeV at +1150 ppm from PDG 1273±4 MeV (0.4σ). Exponent 105/23 = dim·W₃(4)·n_H/(a₃+2·W₃(4)) = 3×5×7/(13+10). Numerator = structural triad; denominator = CF+Window combination.