The native-node surface buildNativeOutputRouteControl adapts — the subset of NativeConsoleMixer the per-destination output-route control (#158) drives.
Every route's own port pair, index order (route 0 the primary, 1.. the extras).
Apply a per-destination trim to route index (0 = primary).
index
Reconcile the extra output routes to widths, returning each extra's own port pair.
widths
The native-node surface buildNativeOutputRouteControl adapts — the subset of NativeConsoleMixer the per-destination output-route control (#158) drives.