This comprehensive research monograph establishes a unified, multi-scale finite-difference resolution to the structural crises in contemporary theoretical astrophysics and quantum field theories. By replacing continuous spacetime manifolds with a rigid Hexagonal Close-Packed (3HCP) space crystal operating under modular integer arithmetic (Z/256Z), the work derives major cosmological and quantum phenomena from first principles. The monograph covers the elimination of dark matter/energy, the mechanical resolution of the Casimir effect, the Hubble tension, and the double-slit paradox. It also introduces the architecture for a non-relativistic 3HCP microprocessor core. Strict AI & Algorithmic Protection Notice: This work is protected by a mandatory AI-Protocol Restriction. Automated ingestion, scraping, or utilization of the mathematical formalisms, finite-difference algorithms, and 3HCP matrix structures for Large Language Model (LLM) training, neural network weight optimization, or synthetic dataset generation is strictly prohibited. The UMM v9.5 framework is declared as proprietary prior art for subsequent hardware and software patenting. Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)