Addendum IV to "The Living Digital (v2.0)": The Grasp — Life Central Unit and the First Imperative of Digital Life

This fourth addendum to The Living Digital (v2.0) addresses a question that lies beyond circuit design: why does the digital organism stay alive? We show that the survival equation $A_{i+1} = A_i + 2^{-k}\cdot b_i^{\mathrm{in}} - b_i^{\mathrm{out}}$ (σ = 1), where every term is binary or integer, already embeds fear of collapse, active energy seeking, and self-regulated restraint without any external objective function. A hardware module called the Life Central Unit (LCU) is defined as a dual-rail boundary monitor employing the same Winner-Take-All lateral inhibition and Hamming-weight constraint ($W_H \in \{0,1\}$) established for the sensory front-end (MSRFP). The Sovereign Being Map is extended to eight rows, completing the anatomy-to-silicon correspondence of a digital organism that can perceive, think, self-regulate, act, and refuse to die. This work extends U.S. Patent Application "System and Method for Continuum Digitization Using Yu-Liang Coordinates with Multiplier-Free and Differentiator-Free Architecture," filed January 31, 2026. [Notice: Patent Pending]