V76: Operational Σ-Space Hook — Probing Dynamic-Space Structure through Orbit Prediction Residuals

The V70–V75 sequence established a scale-crossing language in which forces act as active Σ-operators and gravity appears as accumulated geometric residue, with particle mass interpretable as Σ-maintenance cost tied to a dynamic-space cutoff κ. We now propose an operational stress-test: the near-Earth environment, where satellite constellations, debris fields, and dense tracking operations create conditions in which the usual assumption of a quasi-clean, time-stationary background may break down. We do not claim that electromagnetic traffic produces measurable gravitational fields. Rather, we propose three operationally testable diagnostics—Prediction Error Growth (PEG), Whitening Failure of Residuals (WFR), and Alert Saturation Index (ASI)—that can be evaluated using standard orbit determination products. PEG measures how swiftly predictive accuracy degrades; WFR detects persistent autocorrelation or 1/f structure where white noise is expected; ASI quantifies when alert volume begins to distort decision capacity. These diagnostics serve as operational proxies for the theoretical quantities κ_eff (effective resolution) and Σ_noise (accumulated residual structure). Any team with OD residuals, CDM logs, or maneuver records can compute these metrics and test regime dependence without adopting new dynamics. The hypothesis is falsifiable: absence of systematic correlations with environmental crowding implies the operational Σ-proxy interpretation adds no value. V76 thus provides a "second-cycle entry point" where "space as a clean background" becomes an empirical assumption to be tested rather than an axiom.