Merge branch 'feature/agentserver-durable-tasks' into feature/agentserver-responses-spec016

Author: RaviPidaparthi

sdk/agentserver/azure-ai-agentserver-core/azure/ai/agentserver/core/durable/_client.py

@@ -331,7 +331,7 @@ def _build_default_policies(
     """
     return [
         RequestIdPolicy(),
-        HeadersPolicy(),
+        HeadersPolicy(base_headers={"Foundry-Features": "Routines=V1Preview"}),
         UserAgentPolicy(base_user_agent=_USER_AGENT),
         # Retry on 5xx and the standard transient HTTP statuses; 409
         # is explicitly NOT in retry_on_status_codes (FR-030) because