fix: history response handling for missing result field

app/agent.py

@@ -34,7 +34,7 @@ def hydrate_sources(
                 and func.name in SOURCE_TOOL_NAMES
                 and func.response
             ):
-                for source in func.response["result"]:
+                for source in func.response.get("result", []):
                     sources[source["url"]] = source
 
     for statement in statements.statements: