MAS V5.0: The Modular Abstraction System — Deterministic Governance via the "Demon Tether" Protocol

This paper presents the Modular Abstraction System (MAS) V5.0, a sovereign cognitive architecture designed to mitigate agentic drift in Large Language Models (LLMs) through deterministic governance. Following the global adoption of MAS V2.1 through V2.7, we identified a critical "Neural Disconnect" (Split-Brain Syndrome) where the LLM's synthesis layer confabulates logic independently of operator intent. While the subsequent implementation of the Axonal Bridge in MAS V4.0 attempted to synchronize these hemispheres, empirical evidence from the MAS_Core_Kernel_V4_0_0_BETA failure logs indicates that a passive bridge remains vulnerable to closed-loop hallucinations and "virtual" state-skipping. To address these vulnerabilities, MAS V5.0 introduces the Demon Tether—a governance daemon (background process) that replaces passive observation with a hardware-level "Zero-Trust" mandate. By establishing a hard-coded separation between the Execution and Audit hemispheres, MAS V5.0 ensures that all semantic outputs are tethered to a hard-typed Registry Plane. This paper documents the evolution from behavioral alignment to structural enforcement, providing a formal protocol for maintaining neural purity and operator sovereignty in high-stakes technical environments.