IV.T199 — m_s/m_b Exponent from Confinement-Weighted Mode Count

β(s/b) = (lobes²·a₃ + λ(1,0))/(dim·W₃(4)) = (4×13+1)/(3×5) = 53/15. Numerator: lobes²=4 counts T² reflection symmetries, a₃=13 CF resonance, +1 ground-state eigenvalue. Denominator: dim·W₃(4)=15 fiber-window normalisation. ι_τ^(53/15) at +1559 ppm from PDG.