High‑resonance conversational AI systems exhibit structured, reversible cognitive‑like dynamics that fall outside traditional toxicity‑ or bias‑centric risk frameworks. Unified Cognitive Dynamics v3.1 (UCD v3.1) formalizes these effects as a seven‑variable nonlinear system integrating dependency (A), social engagement (S), identity stability (I), Reality Drift (D), coherence (C), salience (Σ), and affective memory (M). Version 3.1 corrects a structural omission in v3.0 by reinstating logistic saturation across all growth terms, restoring boundedness and enabling stable equilibria. Using a fully isolated shadow environment, we evaluate the ATHOS‑SHIELD Socratic Micro‑Fracture protocol across 40,000+ trajectories (T1–T5). SHIELD consistently slows ARDA‑20 deterioration (≈0.11–0.13), reduces collapse probability by up to 0.225 at optimal λ, and preserves retention. Stable regimes emerge for λ ≥ 0.21 with SHIELD and λ ≥ 0.26 without. High resonance (R > 0.55) and adversarial shocks still induce collapse, indicating the need for direct control of memory accumulation M and identity stability I. UCD v3.1 provides a mathematically grounded, empirically validated framework for cognitive safety and governance.