GCFT CDN-184: The Surface Finds the Moving Peak

CDN-184 builds a compact velocity-resolved signed response surface for the CDN-179 force integrand at \(θ20\). It scans probe velocity from the fitted acoustic-floor speed through and above the finite-time CDN-179 force maximum, retaining direct force, signed negative spectral mass, and response-band centroids. The surface peaks consistently track the finite-time \(v^*(θ)\) branch rather than deriving the asymptotic acoustic floor. D9 remains open, with the next target identified as the \(θ\)-drift of the velocity-response surface.