Observing the Reversal: Seeing the Past — The Milky Way: A Blind Geometric Closure Test of the Milky-Way Archival Self-Image

Paper XV — Observational Continuation of the Six-Throat Directed Geometry Program. This work applies the theoretical optical-history construction of Paper XV to the Milky Way and performs a blind geometric-closure test using the NASA-Sloan Atlas v1_0_1 catalog. Before catalog identities were exposed, the rotation-invariant two-node angular target was fixed at 920.350654305343 arcsec with a primary half-width of 0.007 arcsec. The complete eligible catalog contained 641,409 objects, corresponding to 205,702,431,936 unordered trials. The blind primary search returned 179 pairs inside the frozen interval. A deterministic ensemble of 1000 block-preserving null realizations produced no realization with a count reaching or exceeding the observed value, giving the frozen empirical statistic p_global = 1/1001 = 0.000999000999000999. The minimum-residual geometrically selected pair is NSAID 13504 and NSAID 13535, with a catalog-coordinate separation of 920.3506367089722 arcsec and an absolute residual of 17.596370867 microarcseconds from the theory-fixed target. This pair is designated Primary Follow-up Pair No. 1 for independent high-resolution observational study. This record is the observational continuation of the theoretical Paper XV record: DOI 10.5281/zenodo.22878327. The accompanying Zenodo bundle contains the manuscript source, frozen preregistration, MW-A18 catalog executor, follow-up extraction code, scientific figures, reproducibility documentation, reference metadata, and SHA-256 integrity records.