fix: keep Python executable packaging inside the deployed closure

scripts/smoke-python-runtime.py

@@ -1361,6 +1361,8 @@ def smoke_sdk_dynamic_tools(base_url: str, executable: Path, update_snapshots: b
                 "DSH_PERMISSION_MODE": "danger-full-access", "DSH_TELEMETRY_DISABLED": "1",
                 "HOME": str(user_home), "USERPROFILE": str(user_home),
                 "DSH_AGENTS_HOME": str(user_home / ".agents"),
+                # Pin the tool baseline independently of optional resources in the host cache.
+                "DSH_PRIMARY_RUNTIME": "",
             },
             api_key="sk-keyless-smoke", base_url=base_url, request_timeout_seconds=60,
         ) as harness: