PrivatelastPrivatelastRecord the current version at tick; resets the settle clock on change.
True once the version has been unchanged for ≥ settleTicks frames.
Forget the observed version and clock — for a registry that restarts its
tick at 0 (clear()), so the first observation of the new scene re-seeds
the clock instead of comparing against a tick from the old one.
Tracks when the (global) view-update version last changed, in registry ticks, so the selector can tell whether the view has "settled" (stopped scrubbing). Single instance per registry — the version is global (one
getViewVersion).