The Higgs-to-Z Mass Ratio from the Face Laplacian Spectrum

The ratio m_H/M_Z = 18/(9+√17) = 1.37163 is predicted from the face Laplacian spectrum of the truncated octahedron with zero free parameters. The prediction uses λ_A₂u=9 (Higgs sector, spectral maximum) and λ_T₁u_hi=(9+√17)/2 (upper weak sector). Predicted m_H = 125.08 GeV; observed 125.25 ± 0.17 GeV. Agreement: 0.97σ, 0.14%. This is the third spectral ratio prediction from the same face Laplacian: Koide angle (exact), solar neutrino mixing (0.49σ), and Higgs/Z ratio (0.97σ). All three contain √17 = √(C_A⁴−4(C_A+1)²) — the discriminant of the single T₁u characteristic equation λ²−C_A²λ+(C_A+1)²=0 with C_A=3.