Model specification: Moving-carrier comparison library

After the comparator $G_s$ has been selected, allow:

1. stationary qubit memories at declared sites;

2. mobile qubit carriers whose centres follow preprogrammed future-causal curves of $G_s$, with identity internal propagation;

3. local SWAP gates only while a carrier and memory are coincident;

4. an external calibrated clock and controllable gate generators.

These are added resources, not operations obtained from the original one-use processes.