Ghost a node whose ports are absent — a stopped stream keeps its node in the enumeration but
its ports unregister (#168's present-node-unregistered-ports case).
Applied where the view is RECORDED, so every reader of /patchbay/nodes sees the same marks.
A mark applied on the way OUT of one door would leave the other door's readers disagreeing
with it.
Ghost a node whose ports are absent — a stopped stream keeps its node in the enumeration but its ports unregister (#168's present-node-unregistered-ports case).
Applied where the view is RECORDED, so every reader of
/patchbay/nodessees the same marks. A mark applied on the way OUT of one door would leave the other door's readers disagreeing with it.