Fix logging in AgentNode's step callback in graph.py to display action directly instead of action step, improving clarity in debug output.

graph.py

@@ -64,7 +64,7 @@ class AgentNode:
         # )
 
         step_callbacks: Optional[List[Callable]] = [
-            lambda step: logger.info(f"Step {step.step_number} completed: {step.action_step.action}")
+            lambda step: logger.info(f"Step {step.step_number} completed: {step.action}")
         ]
 
         self.agent = CodeAgent(