RLDS II: Regime-Limited Dynamical Systems — Theory and Reduction Criteria for Singular ODEs

Part II of the RLDS series. This paper formulates the canonical RLDS framework. It introduces the general class of Regime-Limited Dynamical Systems, defines the thresholds κc, κbdy, and κadm, distinguishes monotone and unimodal geometries of the auxiliary function, and provides explicit reduction criteria (C1–C4) for embedding external models into the RLDS class. Paper I: singular-attractor prototype mathematics. Paper II (this work): canonical RLDS framework and reduction criteria. Paper III: paired observational signature. Paper IV: cosmological consequences under RLDS closure. Paper V: representative microphysical descent to RLDS.