Atlas of Coherence Regimes (ARC-RCD): A Map of Where Coherence Lives, Convives, Dies, and Does Not Matter (v1.1)

The Atlas of Coherence Regimes (ARC-RCD) classifies physical systems into five regimes based on the role of quantum coherence: Lives (Regime I), Convives with Noise (Regime II), Dies (Regime III), Does Not Matter (Regime IV), and Thresholds (Regime V). Grounded in Radial Coherential Dynamics (RCD) and validated against experimental parity oscillation data from IonQ Forte, IQM Garnet, Rigetti Ankaa-3, and IBM Heron processors, it serves as a classification and exclusion tool for experimentalists, theorists, and engineers. The Atlas does not advocate for universal quantum advantage; it identifies where coherence is physically relevant and where it is not. Living document v1.1.