Terminal-like nodes have no outputs at all: the catalog client type and
the non-catalog output/error supernode boundary pseudo-nodes
(src/graph/expand.rs). src/graph/validation.rs::validate_supernode
forbids outgoing edges from output/error and allows an unwired error
boundary, so these must never be asked to wire a success port.
Terminal-like nodes have no outputs at all: the catalog
clienttype and the non-catalogoutput/errorsupernode boundary pseudo-nodes (src/graph/expand.rs).src/graph/validation.rs::validate_supernodeforbids outgoing edges fromoutput/errorand allows an unwirederrorboundary, so these must never be asked to wire asuccessport.