Rationale
No task can be completed while any question on this branch is unresolved; it can still be finished as blocked, partial, no_match or failed.
Required behaviour
No task is accepted as completed while any question on the branch is unresolved.
Failure behaviour
A violation is a FAIL finding under the category blockers, and the command that found it exits 10. Under watch the same violation is reported as drift and the command exits 11.
Verification
mj_validate_blockers decides it, dispatched from check, finish. The behavioural case test/cases/17_doctrine_enforcement.sh proves it, and CI runs that case.