IV.D355 — Strong CP Resolution: SA-i Forbids Topological C-Sector Charge

SA-i admissibility on C-sector carriers (η-winding mod 3) forbids instantons: Δ(η-winding) = ±1 ∉ 3ℤ violates SA-i. Therefore topological charge Q_top = 0 and θ_QCD = 0 exactly. This resolves the strong CP problem from the τ-axioms (K3+K5) alone.