fix(auto_router): flag name field and tier fields together on empty submit

Clicking Add Auto Router with the name empty returned early with only a
toast, so blank tier selects never got their inline error state. The
empty-name branch now sets showValidationErrors and triggers antd
validation on the name field, so every unfilled mandatory field is
flagged at once. Adds a regression test for the tab component.

ui/litellm-dashboard/src/components/add_model/add_auto_router_tab.test.tsx

@@ -0,0 +1,40 @@
+import { renderWithProviders, screen } from "../../../tests/test-utils";
+import userEvent from "@testing-library/user-event";
+import { vi } from "vitest";
+import { Form } from "antd";
+import AddAutoRouterTab from "./add_auto_router_tab";
+import NotificationManager from "../molecules/notifications_manager";
+
+vi.mock("../networking", () => ({
+  modelAvailableCall: vi.fn().mockResolvedValue({ data: [] }),
+}));
+
+vi.mock("@/components/llm_calls/fetch_models", () => ({
+  fetchAvailableModels: vi.fn().mockResolvedValue([]),
+}));
+
+vi.mock("./handle_add_auto_router_submit", () => ({
+  handleAddAutoRouterSubmit: vi.fn(),
+}));
+
+vi.mock("../molecules/notifications_manager", () => ({
+  default: { fromBackend: vi.fn() },
+}));
+
+const Harness = () => {
+  const [form] = Form.useForm();
+  return <AddAutoRouterTab form={form} handleOk={vi.fn()} accessToken="token" userRole="Admin" />;
+};
+
+describe("AddAutoRouterTab", () => {
+  it("flags every mandatory field when Add Auto Router is clicked with nothing filled", async () => {
+    const user = userEvent.setup();
+    renderWithProviders(<Harness />);
+
+    await user.click(screen.getByRole("button", { name: /add auto router/i }));
+
+    expect(await screen.findByText("Auto router name is required")).toBeInTheDocument();
+    expect(screen.getAllByText("This tier is required")).toHaveLength(4);
+    expect(NotificationManager.fromBackend).toHaveBeenCalledWith("Please enter an Auto Router Name");
+  });
+});

ui/litellm-dashboard/src/components/add_model/add_auto_router_tab.tsx

@@ -198,6 +198,8 @@ const AddAutoRouterTab: React.FC<AddAutoRouterTabProps> = ({ form, handleOk, acc
   const handleAutoRouterSubmit = () => {
     const name = form.getFieldValue("auto_router_name");
     if (!name) {
+      setShowValidationErrors(true);
+      form.validateFields(["auto_router_name"]).catch(() => undefined);
       NotificationManager.fromBackend("Please enter an Auto Router Name");
       return;
     }