Merged Draft — Decay–Dynamic Equilibrium (DDE) + Operational Indices (Paper 1 + Paper 2) Version 2.0

This working paper merges a conceptual frame, the Decay–Dynamic-Equilibrium (DDE) model and the Law of Persistence, with an operational measurement layer designed to make theory testable and actionable. The conceptual layer (Part I) explains how systems across scales undergo cycles of Comfort → Decay → Renewal and why interventions (timed and shaped correctly) restore dynamic equilibrium and persistence. The operational layer (Part II) introduces a suite of indices (Atrophy Horizon, Latent Potential Index, Regeneration Cost-Renewal, Persistence Signature) and formal decision rules to trigger interventions and evaluate outcomes. We provide measurement protocols, mapping templates for three pilot domains, and simulation experiments to validate indices. By keeping the theoretical spine intact and attaching a rigorous metric engine, the paper converts conceptual insight into testable hypotheses ready for pre-registration and pilot deployment. The unified approach accelerates empirical validation while preserving cross-disciplinary communication needed for adoption.