Item F4: A pointer into a superseded source tree still resolves — *closed*

Closed by tests/dead_pointers.py, which checks that every rooted path a live document cites resolves and that a citation into a tree declared disposable or superseded says which. Both failures were invisible to every other gate, because both are files that exist. The corpus-reconciliation round paid the second by hand across seven pointers, one of which had materially changed.