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

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

tests/unit/methodCardCustomizeUnloadBlocked.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import {
+  captureMethodCardCustomizeSnapshot,
+  isMethodCardCustomizeUnloadBlocked,
+} from "../../lib/create/methodCardCustomizeSession";
+
+const HEADER_0 = { title: "", description: "" };
+
+describe("isMethodCardCustomizeUnloadBlocked", () => {
+  it("is false when the modal is closed or snapshot is missing", () => {
+    const snap = captureMethodCardCustomizeSnapshot({ x: 1 }, null, HEADER_0);
+    expect(
+      isMethodCardCustomizeUnloadBlocked(false, snap, { x: 2 }, null, HEADER_0),
+    ).toBe(false);
+    expect(
+      isMethodCardCustomizeUnloadBlocked(true, null, { x: 2 }, null, HEADER_0),
+    ).toBe(false);
+  });
+
+  it("is true only when the open modal is dirty", () => {
+    const snap = captureMethodCardCustomizeSnapshot({ x: 1 }, null, HEADER_0);
+    expect(
+      isMethodCardCustomizeUnloadBlocked(true, snap, { x: 1 }, null, HEADER_0),
+    ).toBe(false);
+    expect(
+      isMethodCardCustomizeUnloadBlocked(true, snap, { x: 2 }, null, HEADER_0),
+    ).toBe(true);
+  });
+});