Canonical Regime Certification

We present a canonical, projection-based framework for certifying effective physical regimes and diagnosing the existence or breakdown of action principles in non-Markovian quantum systems. Rather than postulating a fundamental dynamical law, the framework takes as input a structural data package and produces regime classification, stability certificates, and action-existence results. We demonstrate how unitary, Lindblad, non-Markovian, and structurally critical regimes arise as distinct regions in regime space, and show that the existence of an effective action is a regime-dependent, non-universal property.