Kinetic Coupling and Polarization-Resolved Dispersion in a Micropolar FCC Medium: A Constitutive Model Motivated by Tension Field Theory

We derive the leading transverse transport tensor of a specified face-centered-cubic (FCC) node–pore model motivated by Tension Field Theory. The construction combines objective contact mechanics, reversible pore displacement–orientation coupling, a clamped–relaxed potential, and common/internal kinetic overlap. The principal result is the acoustic reduction of this joint action: in an explicitly defined one-amplitude family, the leading correction has the matrix form A(λ) = A_cl - λS + X - λ⁻¹T_m. The overlap terms cannot generally be recovered from static stiffness relaxation alone. Exact cell integration gives the orbital ratio I_D / (M_D d_nn²) = 1/8 under uniform kinetic density and common rigid co-rotation. Four principal transverse coefficients reconstruct the leading reciprocal cubic angular symbol; we give explicit off-axis predictions and necessary and sufficient conditions for absence of polarization splitting at this order. An analytically energy-admissible finite-Ritz realization exhibits either sign of the leading speed departure without fitting a dispersion target. A separate, conditional photon interpretation converts the adopted LHAASO quadratic time-of-flight threshold into r_D √|a_ν| < 1.40948 × 10⁻²⁸ m when propagation conventions are matched. The contribution is the specified coupled constitutive reduction and its reproducible polarization-resolved consequences, not a derivation of Maxwell theory or evidence that the physical vacuum has an FCC structure.