Surface Obstruction and Conformal Common-Ray Reduction of the Coupled Two-Projection Transport

This paper audits the coupled common‑ray transport and shows a sharp altitude separation: at the surface level the dyad‑covariant divergence system is obstructed by symmetric derivative terms, while on the homogeneous sector it degenerates conformally into four scalar transports with holonomy given by inverse root volume and the Nieh–Yan phase. The coupled reduction owns a frozen invariant and a resonance‑free memory law, completing the exclusion of the two‑edge shared‑holonomy signature.