IV.R431 — Exponent Universality: All Ratios from W

3/7 quark mass exponents now derived from first principles (m_t/m_b, m_c/m_t, m_u/m_n). All 7 decompose over dictionary {dim(τ³), a₃, |lobes|, W₃(4), n_H}. No exponent requires input beyond ι_τ and τ-axioms.