ctrlrun.Grant — class, defined at src/ctrlrun/authority.py:299
__post_init__ validates everything the YAML loader validates, so the constructor refuses
exactly what the loader refuses. That is not decoration: Control.delegate takes a Grant
built in Python, and §5.5’s segment relation is undefined on a segment like a**, so
without it item 3’s containment check would be discharging a proof about a value nothing
validated.