Black Holes as Saturation Limits of Observer Normalized Coherence

This paper provides a boundary-condition analysis that completes the internal logic of the observer-normalized coherence framework introduced in earlier work. Within that framework, clocks and rulers are locally defined by spacetime curvature, and apparent large-scale anomalies arise when intrinsically non-equivalent regions are compared under a single normalization. The present work identifies black holes as the saturation limit of global physical inference rather than as sites of physical breakdown. Event horizons, infinite redshift, and apparent singular behavior are interpreted as indicators that coherence requirements have exceeded the domain in which global normalization remains possible. Local physical laws and general relativity are preserved throughout, and no new dynamics or degrees of freedom are introduced. This paper is intended as a conceptual closure rather than an extension or revision. It defines the boundary at which global comparison ceases to be coherent under observer-normalized inference and clarifies the role of black holes and the vacuum as limiting cases of observability.