DCRP101 / X72R84: Joint-Path Young Profile and the Second/Third-Moment Lock

Following DCRP100's selected high-leverage transport–Riesz branch C_TRΓ^{ℓ*}, this round tests whether the Kelvin second-moment Young profile already forces the transport–Riesz sign, and proves the negative with an explicit Rademacher-coupling counterexample: the one-factor marginals and pairwise marginals can be made completely identical while the mixed third moment can still be positive, zero, or negative, so no theorem that derives the sign from second moments or pairwise correlations alone can hold. Together with a scope repair between DCRP100's finite-lag Duhamel term and the X72 Round38 defect-energy pairing, this round fixes the surviving paradigm as a joint-path covariance lock carrying both the Kelvin second-moment lock and the transport–Riesz mixed-third-moment lock simultaneously, reducible via DCRP66's 4:1 identity only on the zero-lag defect-energy subbranch. The conclusion leaves the next round to determine whether the pulled-back X72 adjoint test can maintain a fixed sign correlated with this third moment under a fixed lag.