Respect no-auth LearnHouse operations

agent.py

@@ -376,12 +376,7 @@ class Learnhouse(A2AAgent):
         if requirements is None:
             requirements = ROOT_SECURITY
         if requirements == []:
-            token = _consumer_secret_optional(ctx, "LEARNHOUSE_API_KEY")
+            return {}, {}
-            if not token:
-                raise ConsumerSetupMissing(
-                    "operation requires consumer setup secret(s): LEARNHOUSE_API_KEY"
-                )
-            return {"authorization": _learnhouse_auth_header(token)}, {}
         missing: list[str] = []
         for requirement in requirements or []:
             if not isinstance(requirement, dict) or not requirement: