IV.T197 — Up Quark Direct Mass from Exponent Duality at +395 ppm

m_u = (17/20)·ι_τ^(11/2)·m_n = 2.161 MeV at +395 ppm from PDG 2.16±0.07 (<0.02σ). Replaces chain prediction (+31043 ppm), 79× improvement. Geometric mean: m_u·m_t = (17/20)²·ι_τ^(1/|lobes|)·m_n² = 372617 MeV². Exponent 11/2 = (2W₃(4)+1)/|lobes|.