Dark Energy from R3⊕I 3 Planck-Patch Geometry

We model physical space as a real sector R3 and an adjoint, evanescent sector I3 that couple only across Planck-area Planck patches on a common interface Σ. We postulate three interface microfacts: (P1) each patch on Σ has area Apatch = 4L^2P ; (P2) by the Bekenstein–Hawking area law, the per-patch capacity is 1 nat; (P3) the initial uniform ledger load is one bit per patch, i.e. x = Spatch =ln 2 nats. A local, capacity-limited exchange along Σ conserves the total ledger load and drives theinterface to an absorbing state with saturated fraction fsat = x = ln 2. Mapping the homogeneous saturated ledger to vacuum energy yields ΩΛ = fsat = ln 2 and Ωm = 1 − ln 2, in quantitative agreement with Planck 2015 (0.692 ± 0.012) and within ∼1.2% of Planck 2018 (0.685 ± 0.007) [5, 6] The mechanism is testable: after equilibration dfsat/d ln a = 0 and w = −1. On-shell R3 physics is unchanged; I3 supports only evanescent modes (vanishing time-averaged Poynting flux).