Spot-check of the new H-C1 hook code found the owner-only-elevation gate was
bypassable: it skipped any member ALREADY privileged in the parent, but since
Admin is also "privileged", an Admin→Owner promotion was skipped and accepted —
the exact escalation the gate exists to stop, and a failure of its own paired
test. Gate now skips only UNCHANGED roles (parent role == new role), so every
change into a privileged role (Member→Admin/Owner, Admin→Owner, new privileged
member) requires an owner signer.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>