IV.D366 — k=15/2 Baryogenesis-Lepton Duality: Shared Exponent 15 = dim(τ³)·W₃(4)

Baryogenesis-lepton duality: the exponent 15 = dim(τ³)·W₃(4) = 3·5 governs BOTH η_B suppression (Book V: η_B = α·ι_τ¹⁵·(5/6)) AND m_μ/m_e NNLO correction (Book IV: k=15/2 = 15/|lobes|). The factor 1/2 = 1/|lobes| distinguishes fiber-level (particle mass) from base-level (cosmological) observables. This links the micro-macro duality of Books IV-V through a single Window-algebra exponent.