We show that the architecture of particle physics follows from a single primordial contrast: gravity (space, extension) and the operational speed limit (the rate at which change propagates, later identified with c). This is not an invented primitive. It is the logical endpoint of walking back the early universe's force splits: at the Planck epoch all interactions were unified into a single superforce. The first to separate was gravity — the geometry of space itself — because for anything to change, the temporal constraint on change must already exist. Those two poles of the primordial interaction — space (extension) and the operational speed limit (temporal constraint) — are the founding contrast. They are antiparticles that cannot annihilate. From this seed, checked by the Lean 4 proof assistant with zero sorry and zero axiom, the following are derived without free parameters: an arrow of time, exactly three spatial dimensions (forced by loop-closure combinatorics),spin-½ and the spin-statistics connection (from loop parity),color confinement (free single colors structurally impossible),the unique fractional charge multiset {⅓, ⅔} (Diophantine partition of 9),the twelve-fermion flavor census (from oriented lattice directions),the gauge sector structure 8+3+1 (swap-minus-singlet on forced cardinalities),a universal speed limit and time dilation (the operational speed limit IS the seed),the inverse-square law (conserved flux in 3D),dark energy as a vacuum property with w = −1 (combinatorial curvature invariant),a gauge-sterile dark sector (Phase 3 of the ℤ₆ cycle),maximal parity violation, and exact matter/antimatter balance forbidden.The combinatorial integers 137 and 1836 arise as lattice invariants at the hadronic scale. The formalization accompanies this paper as a supplementary Lean 4 source file.