feat(frontend): modernize Angular app

ui/src/app/app.spec.ts

@@ -0,0 +1,33 @@
+import { TestBed } from '@angular/core/testing';
+import { App } from './app';
+
+vi.hoisted(() => {
+  Object.defineProperty(window, "matchMedia", {
+    writable: true,
+    enumerable: true,
+    value: vi.fn().mockImplementation((query) => ({
+      matches: false,
+      media: query,
+      onchange: null,
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+      dispatchEvent: vi.fn(),
+ })),
+ });
+});
+
+
+describe('App', () => {
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [App],
+    }).compileComponents();
+  });
+
+  it('should create the app', () => {
+    const fixture = TestBed.createComponent(App);
+    const app = fixture.componentInstance;
+    expect(app).toBeTruthy();
+  });
+
+});