Expand return types on Agent

Author: tomusher

src/django_ai_core/contrib/agents/base.py

@@ -56,7 +56,7 @@ def _derive_parameters_from_signature(cls) -> list[AgentParameter]:
         return parameters
 
     @abstractmethod
-    def execute(self, *args, **kwargs) -> str:
+    def execute(self, *args, **kwargs) -> str | dict | list:
         """Execute the agent"""
 
     def __init_subclass__(cls, **kwargs):