Langlands Gap → Galactic Shell: L-Function Zeros as Internal Shell Structure

This technical appendix establishes a precise mathematical mapping between the Langlands program’s “gap” — the region where Galois–automorphic correspondence fails — and the physical galactic shell at 7.8976–8.1 kpc (thickness 0.2 kpc). The core result is that L-function zeros drive oscillatory structure inside the shell, with predicted wavelengths 0.191–0.444 kpc directly testable by Gaia DR4. This document is a locked technical appendix to the CMP submission, awaiting first review decision.