Theorem: Reference-preserving certificate transport

The route transmits the unknown finite payload exactly, including every untouched reference, and forwards its complete classical certificate history. Every non-output payload register ends in a payload-independent blank. All communication dependencies are causal in the supplied metric. Orthogonal sender payloads give a receiver trace-distance contrast one.

Proof. After hop $j$, the sender payload factor and all its reference correlations occupy station $j$; every other payload register is blank. Tensor-factor exchange proves this by induction. Copying an already classical history preserves its joint correlations and is not cloning an unknown quantum state. Each carriage speed is $1/2$ in developed units; local processing and buffering are timelike. The receiver controls are used only after their classical inputs arrive. For the contrast use $|0⟩⟨0|,|1⟩⟨1|$ on one payload qubit.