feat(agent-runner): enforce 4.x host-owned execution

tests/unit_tests/command/test_operator.py

@@ -198,7 +198,7 @@ class TestCommandOperatorBase:
         # Should not raise
         import asyncio
 
-        asyncio.get_event_loop().run_until_complete(op.initialize())
+        asyncio.run(op.initialize())
 
     def test_execute_is_abstract(self):
         """execute() must be implemented by subclass."""