DCRP65 / X72R48: Disproof of Pressure-Source Flatness and Null-Channel Closure

Building on DCRP64's closure of X72 Round38's N1 null channel, this round handles the remaining N2 (pressure source δq=0) and N3 (velocity δV=0). Using the proper divergence representation of the pressure source, q=∂i∂j(ViVj), together with DCRP30's strict DSS sublinear energy tail, it proves that a globally constant pressure source must be zero; DCRP62's exact pressure-response formula for the aligned branch then shows this again forces the neutral stretching rate to satisfy λ'+λ+λ²=0, which after period integration contradicts the non-negativity of λ². N3 is dismissed trivially, since a constant velocity kills the vorticity. With this, all three factor-by-factor null channels of X72 Round38 are closed, proving that any surviving silence of the X branch must come from a genuine pairwise support, tensor-angle, or principal-value correlation cancelling among the three individually active increments — the problem is handed to DCRP66 to address this triple-correlation rigidity.