Abstract

We construct a deterministic family of countable, locally finite metric substrates with one fixed partition schedule at each scale. The construction separates transport lanes from junction interfaces. Every junction is updated in one block, whereas the lane interiors are updated by disjoint nearest-neighbor pairs. Increasing directional resolution therefore does not introduce a direction-by-direction service delay.

Under one physical clock, every dependency edge has Euclidean speed at most a prescribed $c>0$. Uniform estimates on the entire substrate, including intermediate lane vertices, prove convergence of both the metric past envelopes and the scheduled pasts to the Euclidean cone. Routing has vanishing excess time uniformly on bounded journeys and from every starting tick. Classical relays have signalling gap one, and quantum transport is the logical identity channel, including arbitrary untouched references.

Every finite acyclic causal circuit of finite-dimensional complete hybrid instruments has an exact logical realization on sufficiently fine substrates. Local replacements admit matched realizations with the same schedule, preparations, routes, and unchanged channels. A fixed-skeleton operational completion is constructed; evaluation, finite composition, and matched locality extend continuously to it. Its compatibility notion retains local interfaces and intervention slots and is stronger than convergence of one terminal probability law.

The construction proves the isotropic operational existence statement for this explicitly declared finite-experiment class. It does not construct a quantum field theory, a product-preserving spacetime observable algebra, Lorentz covariance, or gravitational dynamics. No uniform degree, block-cardinality, interface-dimension, or computational-efficiency bound is claimed.