The set of node ids to keep lit while one node is hovered: the node itself and everything a link touches it through, origin attachments included, so hovering a prompt shows what came out of it.
The connected ids, or null when nothing is hovered.
The set of node ids to keep lit while one node is hovered: the node itself and everything a link touches it through, origin attachments included, so hovering a prompt shows what came out of it.