Holographic Duality in the Concentric Orbital Cosmological Model: A Nested CFT Hierarchy in de Sitter Space and Non-Perturbative Hermiticity of the Inter-Ring Coupling Operator

Paper 5 of the COCM programme. Resolves Conditional Bridge 1 of Paper 4 by developing a holographic duality specific to the COCM — the nested CFT hierarchy. Theorem A derives the central charge c_n = c_0·[rho_Lambda(0)/rho_Lambda(n)]^(1/2) from the Brown-Henneaux formula in de Sitter, identifying the inter-ring dark energy gradient as a central charge difference between adjacent CFTs. Theorem B derives non-perturbative hermiticity of O_boundary for all eta in [0,1] from CFT unitarity. The three transfer modes of Paper 3 are identified as fusion channels. Prediction XI: CFT spectral fingerprint in jet spectra detectable by ATHENA. Companion to DOI: 10.5281/zenodo.19950582, 10.5281/zenodo.19991607, 10.5281/zenodo.20090596, 10.5281/zenodo.20096465, 10.5281/zenodo.20104113. Version 2.0 adds reference to companion Paper 6: Vázquez González (2026g), COCM Compatibility with Planck PR4 and CMB Spectral Corrections. DOI: 10.5281/zenodo.20111260.