chore: tighten scheduling review coverage

tests/scheduling/test_ownership_binding.py

@@ -22,7 +22,6 @@ from tests.scheduling.controlled import (
 )
 from wf_artifacts.runs.store import FileRunStore
 from wf_scheduling.calendar import OneShotSource
-from wf_scheduling.dispatch import StillRunning
 from wf_scheduling.models import Schedule
 from wf_scheduling.ownership import SchedulerOwnership, SecondOwnerError
 from wf_scheduling.poll import Scheduler
@@ -80,13 +79,13 @@ def test_unrelated_held_lock_rejected_before_writes(tmp_path: Path) -> None:
 
     def spy(admission: Any, now: datetime) -> Any:
         calls.append(admission.id)
-        return StillRunning()
+        raise AssertionError("dispatcher must not run without covering ownership")
 
     sched_store = FileScheduleStore(tmp_path / "sched")
     run_store = FileRunStore(tmp_path / "runs")
     ownership = SchedulerOwnership(tmp_path / "other", owner="unrelated").acquire()
     try:
-        sched = _scheduler(sched_store, run_store, ownership)
+        sched = _scheduler(sched_store, run_store, ownership, script={"*": spy})
         intended = ts(2026, 9, 8, 12, 0)
         _due(sched, sched_store, intended)
         with pytest.raises(SecondOwnerError):
@@ -103,9 +102,12 @@ def test_two_lock_dirs_cannot_operate_same_stores(tmp_path: Path) -> None:
     sched_store = FileScheduleStore(tmp_path / "sched")
     run_store = FileRunStore(tmp_path / "runs")
     intended = ts(2026, 9, 8, 12, 0)
-    covering = SchedulerOwnership(tmp_path, owner="covering").acquire()
-    other = SchedulerOwnership(tmp_path / "other", owner="other").acquire()
+    covering: SchedulerOwnership | None = None
+    other: SchedulerOwnership | None = None
     try:
+        covering = SchedulerOwnership(tmp_path, owner="covering").acquire()
+        other = SchedulerOwnership(tmp_path / "other", owner="other").acquire()
+        assert covering is not None and other is not None
         first = _scheduler(sched_store, run_store, covering, script={"*": "hang"})
         _due(first, sched_store, intended)
         assert first.poll(intended)["a"].startswith("admit:run-")
@@ -117,8 +119,10 @@ def test_two_lock_dirs_cannot_operate_same_stores(tmp_path: Path) -> None:
             second.poll(intended + timedelta(minutes=1))
         assert len(run_store.list_runs()) == 1
     finally:
-        covering.release()
-        other.release()
+        if covering is not None:
+            covering.release()
+        if other is not None:
+            other.release()
 
 
 def test_recover_with_unrelated_lock_rejected(tmp_path: Path) -> None: