Unification of the Four Interactions in PODA Observation Geometry Common Dynamics, Gravity–Gauge Coupling, and Quantum Consistency

Physical states and objective observation conditions jointly determine experimental records. Starting from the physical--observation dual-axis (PODA) structure of Physobser Theory, we construct a common dynamics for the parent connection, response projector, matter fields, and spacetime geometry. In the stated chiral and stable-vacuum realization, an internal five-dimensional space splits into three- and two-dimensional blocks; color and electroweak breaking yield the three gauge interactions, while all stresses source the same gravitational field. The common Dirac spectrum relates gravitational and gauge kinetics through \( k_{\rm sp}g_{\rm sp}^2=2\Omega^2 \). Compatible elimination preserves the parent solutions and their physical source responses. The monograph's sequential return becomes an explicit five-dimensional channel: populations, coherence, and time composition determine when a finite return belongs to the continuous dynamics used here. Eliminating the common coupling and running time then gives a direct relation between two return probabilities and three inverse gauge couplings. Fermion anomalies, thresholds, the strong-CP phase, proton partial lifetimes, and vacuum constraints are treated in the same realization. Positive normal-mode reductions retain the leading low-energy spectral relations, but the purely exponential covariance has a high-energy positivity obstruction and is not identified with a complete positive parent quantum theory. The result is a common classical and controlled low-energy quantum realization with explicit source, response, and matching relations. The four physical interactions remain distinct from the geometric direction types XX, XS, and SS.