CP–THEORY: Final Closure of the Cosmological Potential Framework and Laboratory Falsifiability.

This work presents the final theoretical closure of CP–THEORY, a scalar–tensor modification of gravity emerging from a higher-dimensional Kaluza–Klein framework. The model predicts an environmentally screened scalar fifth force, compatible with current experimental bounds, but potentially testable in high-vacuum or resonant laboratory setups. Explicit parameter ranges, density-dependent effective masses, and experimentally accessible regimes are identified, making the framework directly falsifiable. The purpose of this work is not to claim experimental confirmation, but to provide a concrete and testable theoretical target for precision and space-based experiments. Keywords: Modified gravity; scalar–tensor theories; fifth force; environmental screening; Kaluza–Klein; laboratory tests of gravity.