The Hubble Tension and the Trit Mirror Photon: ΔN_eff = 0.206 from Dark Radiation and H₀ = 69.0 km/s/Mpc

The Trit framework (companion preprint: 10.5281/zenodo.20312220) predicts a massless mirror photon from the right-handed gauge sector (mirror U(1)_R). Mirror electron–positron annihilation at T_mirror = 1.87 MeV reheats the mirror photon before SM neutrino decoupling, giving T_γ̃/T_ν = 0.652 today and ΔN_eff = 0.206. This shifts H₀ from 67.4 to 69.0 km/s/Mpc. Tension with DESI 2024: 0.7σ. Detectable by CMB-S4 at 3.4σ. Zero free parameters: M_WR = 1403 GeV, g_Trit = √(3π/35), m_e = 0.511 MeV are independently derived from first principles.