dangling-refs-excluded-from-visited-set

Summary

When the system encounters a reference to a node that doesn't exist yet during propagation, it skips that reference entirely rather than marking it as "already seen." This matters because if someone later creates a node with that same ID, propagation will process it fresh instead of incorrectly treating it as already handled — preventing a subtle bug where the order of node creation could cause some nodes to silently miss status updates.