fix backend job execution fencing and delivery

crates/worker/tests/controller_test.rs

@@ -837,6 +837,39 @@ async fn feature_flags_default_to_core_tool_surface_only() {
     assert!(!names.iter().any(|name| name == "SubWorkerSpawn"));
 }
 
+#[tokio::test]
+async fn backend_job_profile_exposes_only_structured_result_capability() {
+    let workspace = tempfile::tempdir().unwrap();
+    let resolved = ProfileResolver::new()
+        .with_workspace_base(workspace.path())
+        .resolve(
+            &ProfileSelector::source_named(ProfileRegistrySource::Builtin, "backend-job"),
+            ProfileResolveOptions::with_worker_name("backend-job-worker"),
+        )
+        .unwrap();
+    let client = MockClient::new(simple_text_events());
+    let client_for_assert = client.clone();
+    let (worker, _pwd) = make_worker_with_manifest_and_workspace_context(
+        client,
+        resolved.manifest,
+        WorkerWorkspaceContext::with_client(None, Arc::new(AvailableWorkspaceClient)),
+    )
+    .await;
+    let handle = spawn_controller(worker).await;
+
+    handle
+        .send(Method::submit_text(
+            protocol::new_submission_request_id(),
+            "Run the bounded Backend Job.",
+        ))
+        .await
+        .unwrap();
+    wait_for_status(&handle, WorkerStatus::Idle).await;
+
+    let request = wait_for_captured_request(&client_for_assert).await;
+    assert_eq!(request_tool_names(&request), vec!["SubmitBackendJobResult"]);
+}
+
 #[tokio::test]
 async fn enabled_task_and_web_features_register_their_tools() {
     let manifest = r#"