The Weinberg Angle from the Discriminant and Vertex-Face Surplus of the Truncated Octahedron

The electroweak mixing angle is derived from cell topology: sin²θ_W = (Δ - C_A√Δ) / 2(V-F) = (17 - 3√17)/20 = 0.23153. Observed value: 0.23122 ± 0.00003 (0.14% accuracy). The denominator 2(V-F) = 20 uses the same vertex-face surplus V-F = 10 that appears in the fine structure constant 1-loop correction. Zero free parameters. Part LII of the Unified Foam Field Theory.