We develop a unified effective Quantum Gravity Theory (QGT) in which curva-ture, mass modulation, semiclassical backreaction, and large-scale electromagneticspectral organization arise from a single field-theoretic framework. The theory com-bines a renormalizable semiclassical sector with the Electromagnetic Spectral Ef-fective Model (ESEM), predicting the emergence of Radioactive Equilibrium Points(REPs), Equilibrium Spectral Points (ESPs), and the Global Equilibrium SpectralPoint (GESP), offering a natural interpretation of the cosmic microwave backgroundas a global spectral attractor. Phenomenological consequences include spectral-shellstructures around compact objects, fully compatible gravitational-wave propaga-tion, and testable predictions for laboratory and solar-system experiments.