X72-38: Transport–Riesz Commutator Depletion

Picks up Round 37's compression of the remaining nonlocal forcing into the transport–Riesz commutator [u·∇,𝒯_0]q (STOP-C41), and points out that treating this commutator with only a norm envelope was too crude; instead it studies the defect-energy pairing ⟨E,[u·∇,𝒯_0]q⟩ directly. Using the self-adjoint structure of 𝒯_0, incompressibility, and the even-kernel symmetry, it proves the Pressure Self-Commutator Null Identity and an exact triple-increment representation, reducing the regularity burden exactly to the one-total-derivative critical endpoint problem s_u+s_E+s_q=1 (closure follows once this exceeds 1). STOP-C42 (Triple-Increment Endpoint/Critical Dini Gap) hands the gap to the next round to look for a Dini/log endpoint gain.