Rotating Collapse in the Aldred Frame: The Centrifugal Barrier, the Density Cap, and the Spin a Bounced Remnant May Carry

In the Einstein-Cartan spin-torsion frame defined by the Aldred Limit, rho_A = 9.72e54 g/cm^3, non-rotating collapse bounces at rho_A. For a uniform-density core in solid-body rotation with angular momentum strictly conserved, the centrifugal halt radius is R_c = (25/8) a*^2 r_s and the halt density scales as a*^-6. The critical spin above which rotation halts collapse before the cap is a*_crit = 0.566 (M_floor/M)^(1/3), with M_floor = 8.66e13 g: 1.78e-7 at 1.4 solar masses and 9.24e-8 at 10 solar masses. Main result (a negative result for the density cap): for every spin in the published core-collapse progenitor range, rotation halts collapse 23 to 41 orders of magnitude in density below rho_A, and the cap never binds in rotating stellar collapse; reaching it would require removing angular momentum by factors of 10^4 to 10^6 during collapse. The halt lies outside the Kerr horizon only for a* > 0.543. The mass-shedding spin limit of a material remnant at the cap density equals a*_crit identically (0.566 at the floor mass); it is a limit on cap-density material remnants, not on black holes, for which the frame gives no limit below the Kerr bound a* = 1, and observed near-extremal spins are not in conflict with the frame. All results are model calculations from the deposited script (compute.py). AI-use disclosure: Drafted with the assistance of Dave, an AI research system; all computations are reproducible from the included script.