The address normalizer owns one typed negative result for an otherwise valid
address projection. Only that typed result becomes `NonFinalizable`.
Unsupported graph structure is classified by lowering-owned structural
preflight before materialization. Once the mechanical Structured-to-Dataflow
transaction starts, clone correspondence, block replacement, specialization,
pass verification, canonical artifact/view, and tracked-launch failures are
invocation failures; callers may not flatten an owner's entire error channel
into candidate pruning.