Mean Admissibility of the Spine-Normal Defect

This paper establishes mean admissibility for the spine-normal defect associated with the normalized prime residual. It proves that large defect events cannot persist on sets of positive density, providing global averaged control without any pointwise assumptions. No claim is made regarding the Riemann Hypothesis, nor is RH assumed. The result supplies the global measure-theoretic input used by the admissibility framework, but does not address local rigidity or isolated instability. This paper should be read as the first global control layer in the admissibility program.