mesh/merge-gate pass: builds build-agent, mesh-controller → ace, g14, novox, shanks; no bus step; every machine composes with the change as it did without …
The router holds what an open walk touches and tells its result once; it can do so
only if plan-moved names the walk's start and end, the modules and machines it moves,
what a moved tool runner or node-engine carries there, and how long to hold.
