Black Holes in Mittermeier Attractor Theory (Part 3): Horizon-cell laws, constrained interiors, and quantitative reality checks

This paper derives, within Mittermeier Attractor Theory (MAT), one finite-support normalization that connects microscopic black-hole physics to atomic metrology and cosmological horizon thermodynamics without black-hole calibration. The arithmetic–topological MAT source fixes the dimensionless radius R_th = 0.9844349562973788 and entropy S_th = 3.044555715183351 nats before any horizon observable is introduced. Standard horizon thermodynamics then selects a unique Schwarzschild crossing and transports the same continuous entropy coordinate to Schwarzschild, Kerr, and Kerr–Newman horizons. The resulting coordinate fixes an absolute area unit and its thermodynamic conjugate. In the Schwarzschild sector, it closes a scale-reciprocity network among horizon radius, density, transition volume, and curvature. The ultraviolet transition obeys a mass-dependent cube-root law whose coefficient is inherited from the finite support rather than fitted within a black-hole model. Every Schwarzschild mass reaches the same classical audit curvature at its own transition radius. The accompanying bulk–boundary identity proves that independent fixed-information volume cells cannot reproduce the horizon capacity; correlated, nonlocal, or holographic encoding is required. A multi-invariant Hayward comparison shows that matching the transition radius alone does not reproduce the required density, stress–energy, and curvature data. At the opposite endpoint, the independently derived MAT vacuum root places the complete Schwarzschild–de Sitter branch in the same entropy ledger. The Nariai one-third partition thereby acquires an absolute normalization linking the microscopic crossing to the largest neutral static horizon admitted by the same background. Event Horizon Telescope observations and GW150914 provide consistency audits of the retained general-relativistic exterior, while primordial, stellar, and supermassive examples test the predicted scale hierarchy. Together, these results define an overconstrained ultraviolet–infrared architecture in which atomic spectroscopy, the SI Planck reconstruction, stationary horizons, ultraviolet invariants, vacuum closure, and cosmic horizons test one nonadjustable support from independent physical directions.