IV.R414 — OQ k=7.5: SOLVED (τ-effective) after Sprint 7G

OQ k=7.5 SOLVED at τ-effective scope. k = 15/2 = dim(τ³)·W₃(4)/|lobes| = 3·5/2. Baryogenesis-lepton duality: exponent 15 governs both η_B suppression (V) and m_μ/m_e NNLO (IV). Complete NNLO catalog: all 7 corrections Window-universal. Best m_μ/m_e at −8.2 ppm (k=15/2) vs +43 ppm (k=23/3). Downstream: sub-ppm discrimination between the two k values.