sched: address R2 fail-closed and fault-proof findings

tests/wf_api/test_run_admission_path.py

@@ -65,15 +65,26 @@ def test_manual_run_persists_admission_before_dispatch(tmp_path: Path) -> None:
 
 
 def test_fault_before_admission_never_dispatches(tmp_path: Path, monkeypatch) -> None:
+    import wf_api.runs as runs_module
+
     api, store = _api_with_echo(tmp_path / "fault-before")
+    real_write = store._write_json
+    dispatched: list[str] = []
+    real_plan = runs_module.raw_plan_from_artifact
 
-    def _fail_save(admission) -> None:  # type: ignore[no-untyped-def]
-        raise OSError("injected admission failure")
+    def _fail_on_admission(path: Path, payload: object) -> None:
+        if path.name == "admission.json":
+            raise OSError("injected admission failure")
+        real_write(path, payload)
 
-    # Admission persist precedes dispatch in run_deployment ordering: a failure
-    # here must propagate before any run view exists, so no dispatch could
-    # have produced a stopped checkpoint.
-    monkeypatch.setattr(store, "save_admission", _fail_save)
+    def _spy_plan(artifact):  # type: ignore[no-untyped-def]
+        dispatched.append("dispatch")
+        return real_plan(artifact)
+
+    # Real serialization fault at the admission file: nothing after it
+    # (plan building, dispatch, stopped persist) may run.
+    monkeypatch.setattr(store, "_write_json", _fail_on_admission)
+    monkeypatch.setattr(runs_module, "raw_plan_from_artifact", _spy_plan)
     try:
         asyncio.run(
             api.run_deployment(
@@ -84,8 +95,10 @@ def test_fault_before_admission_never_dispatches(tmp_path: Path, monkeypatch) ->
         raise AssertionError("fault must propagate")
     except OSError:
         pass
-    assert store.list_admissions() == []
-    assert store.list_runs() == []
+    assert dispatched == []
+    fresh = FileRunStore(store.root)
+    assert fresh.list_admissions() == []
+    assert fresh.list_runs() == []
 
 
 def test_captured_invocation_freezes_input(tmp_path: Path) -> None: