IV.T194 — τ-Chain Higgs Self-Coupling at +16 ppm

λ_H(τ) = 0.12928 at +16 ppm. Deviation ≈ 2× the m_H deviation (λ∝m²). No standalone ι_τ formula found (best candidate (4+ι_τ)·κ_ω at −4600 ppm). Self-coupling determined by τ-chain, not independent expression.