APPENDIX: Z₁₂ Operator Geometry: A Finite Spectral Model of Torsion, Boundary Compression, and Dissipative Irreversibility: (Technical Summary & Matrix Appendix Companion to "Unified Discrete Operator Geometry on Z₁₂")

Executive Technical Abstract A finite 12×12 operator defined on a cyclic Z₁₂ lattice is shown to support: Torsion via connection-phase asymmetry Boundary-induced spectral compression via radial transport-weight collapse Irreversibility via non-Hermitian real-part eigenvalues All results are derived from explicit matrix constructions. No continuum manifold structure, metric tensor, Einstein field equations, or statistical thermodynamic assumptions are invoked. Spectral splitting collapses continuously as radial coupling vanishes. A quadratic spectral invariant persists under torsion and boundary deformation. This document provides the minimal formal structure and explicit matrix example supporting those claims. Full development appears in the companion paper.