Warn on tab close when create-flow module or wizard edits have not been saved.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/components/CommunicationMethodsScreenPersistence.test.tsx

@@ -6,6 +6,7 @@ import {
   cleanup,
   within,
   waitFor,
+  dispatchBeforeUnload,
 } from "../utils/test-utils";
 import { fireEvent } from "@testing-library/react";
 import "@testing-library/jest-dom/vitest";
@@ -576,4 +577,62 @@ describe("CommunicationMethodsScreen — Add Platform persistence", () => {
     expect(labels[1]).toMatch(/Code of Conduct/);
     expect(labels[2]).toMatch(/Core Principle/);
   });
+
+  it("does not block tab close when the create modal is unchanged", async () => {
+    render(
+      <ScreenWithStateProbe
+        onState={() => {
+          /* noop */
+        }}
+      />,
+    );
+
+    fireEvent.click(
+      screen.getAllByRole("button", { name: /Signal: Encrypted messaging/ })[0],
+    );
+    await screen.findByRole("dialog");
+    expect(dispatchBeforeUnload()).toBe(false);
+  });
+
+  it("blocks tab close while the create modal has unsaved field edits", async () => {
+    render(
+      <ScreenWithStateProbe
+        onState={() => {
+          /* noop */
+        }}
+      />,
+    );
+
+    fireEvent.click(
+      screen.getAllByRole("button", { name: /Signal: Encrypted messaging/ })[0],
+    );
+    const dialog = await screen.findByRole("dialog");
+    const textboxes = within(dialog).getAllByRole(
+      "textbox",
+    ) as HTMLTextAreaElement[];
+    fireEvent.change(textboxes[0], { target: { value: "Unsaved principle" } });
+    expect(dispatchBeforeUnload()).toBe(true);
+  });
+
+  it("blocks tab close while the custom-policy wizard has unsaved edits", async () => {
+    render(
+      <ScreenWithStateProbe
+        onState={() => {
+          /* noop */
+        }}
+      />,
+    );
+
+    fireEvent.click(
+      screen.getAllByRole("button", { name: /Signal: Encrypted messaging/ })[0],
+    );
+    const dialog = await screen.findByRole("dialog");
+    fireEvent.click(within(dialog).getByRole("button", { name: "More options" }));
+    fireEvent.click(screen.getByRole("menuitem", { name: "Customize" }));
+
+    const nameInput = await screen.findByPlaceholderText("Policy name");
+    expect(dispatchBeforeUnload()).toBe(false);
+    fireEvent.change(nameInput, { target: { value: "Renamed in wizard" } });
+    expect(dispatchBeforeUnload()).toBe(true);
+  });
 });