IV.R398 — NLO Correction Factor for m_μ/m_e — Open Structural Identification (OQ-C5a)

The NLO correction to m_μ/m_e = ι_τ⁻⁵ has effective exponent 4.96 (gap δ=0.04 ≈ 1/25), giving ι_τ^(-4.96)=206.832 at +307 ppm (τ-effective). The correction factor f = 206.768/215.919 = 0.9576 lacks a first-principles τ-structural identification. Wave 3A scanned 14 analytic formulas (κ_ω, κ_D², CF window W₃(4)=5, CF convergent a₂=13, fine-structure α, geometric series, higher powers): none achieved within 1000 ppm. Open question OQ-C5a: identify the τ-internal mechanism that shifts the winding eigenvalue from exponent 5 to 4.96, analogous to the EM radiative correction δ_μ = O(α) proposed in IV.R114. The gap 0.04 ≈ α/2 ≈ α·ι_τ^{-1} merits further analytic investigation.