fix(favorites): keep folder selector above detail modal

src/__tests__/unit/FavoriteFolderSelector.test.ts

@@ -0,0 +1,19 @@
+import { render } from "@testing-library/vue";
+import { describe, expect, it } from "vitest";
+
+import FavoriteFolderSelector from "@/components/FavoriteFolderSelector.vue";
+
+describe("FavoriteFolderSelector", () => {
+  it("renders above the app detail modal and its child popups", () => {
+    const { container } = render(FavoriteFolderSelector, {
+      props: {
+        show: true,
+        folders: [],
+      },
+    });
+
+    const overlay = container.firstElementChild;
+
+    expect(overlay?.className).toContain("z-[90]");
+  });
+});