retry invalid artifact body immediately

tests/test_clean_agent_preview.py

@@ -549,12 +549,6 @@ async def test_repeated_off_contract_calls_recover_via_required_artifact_body(mo
             })},
         }]}}]},
         {'choices': [{'delta': {'content': ''}}]},
-        {'choices': [{'delta': {'tool_calls': [{
-            'index': 0, 'id': 'bad-inspect',
-            'function': {'name': 'inspect_media', 'arguments': json.dumps({
-                'path': '/workspace/input.png',
-            })},
-        }]}}]},
         {'choices': [{'delta': {'content': '<html><body>Recovered</body></html>'}}]},
     ])
 
@@ -611,7 +605,7 @@ async def test_repeated_off_contract_calls_recover_via_required_artifact_body(mo
         event.get('type') == 'tool_output'
         and event.get('execution_attempted') is False
         for event in events
-    ) == 3
+    ) == 2
     assert any(
         event.get('type') == 'artifact_body_handoff'
         and event.get('path') == '/workspace/output.html'