We present a coherence-based framework in which causality emerges as a phase-ordered regime of an underlying geometric substrate. The theory unifies cosmic inflation, dark matter phenomenology, black hole structure, quantum measurement, and information-theoretic constraints within a single emergent-causality architecture. The framework reproduces standard ΛCDM background cosmology and linear CMB power spectra while predicting distinctive higher-order signatures, coherence-gated dark matter halo structure, modified inner-halo dynamics, and universal oscillatory features in primordial perturbations. This work emphasizes falsifiable predictions, analytic closures, and observational consistency tests across cosmology and astrophysics.