HSD v0.1.2 — Engineering Specification for Life Steady-State Description

This document defines HSD (Homeostatic State Descriptor) v0.1.2, an engineering specification for life steady-state description. HSD specifies a non-clinical system for describing the steady-state behavior of human life systems by modeling system state using HTMA-derived mineral ratios, wearable-based physiological signals, and temporal dynamics. These inputs are mapped into a low-dimensional state space for objective observation of system stability and deviation. The system is strictly descriptive by design. It does not perform diagnosis, provide recommendations, or offer intervention guidance. Its role is limited to life-system instrumentation and state modeling, analogous to an engineering dashboard that reports system position and longitudinal behavior without directing action. This document constitutes the locked engineering specification for HSD v0.1.2 and serves as an implementation reference, conceptual anchor, and public record of the system definition.