test(issue-268): lock phone audio guard against playback regressions

frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts

@@ -38,7 +38,10 @@ describe('i18n MVP flow smoke (host/player + audio policy)', () => {
     host.ngOnDestroy();
   });
 
-  it('keeps audio routing policy primary-only (client has no audio output)', () => {
+  it('keeps audio routing policy primary-only (client has no audio output)', async () => {
+    const originalPlay = vi.fn().mockRejectedValue(new Error('original play'));
+    const mediaPrototype = { play: originalPlay };
+
     vi.stubGlobal('window', {
       location: { hash: '', search: '' },
       history: { state: null, replaceState: vi.fn() },
@@ -46,16 +49,25 @@ describe('i18n MVP flow smoke (host/player + audio policy)', () => {
       sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
       addEventListener: vi.fn(),
       removeEventListener: vi.fn(),
+      HTMLMediaElement: { prototype: mediaPrototype },
     });
     vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
+    vi.stubGlobal('document', { querySelectorAll: vi.fn().mockReturnValue([]) });
 
     const host = new HostShellComponent();
-    const player = new PlayerShellComponent();
+    host.ngOnInit();
 
-    expect(host.clientHasNoAudioOutput).toBe(true);
-    expect(player.clientHasNoAudioOutput).toBe(true);
+    await expect(mediaPrototype.play()).rejects.toThrow('original play');
+
+    const player = new PlayerShellComponent();
+    player.ngOnInit();
+
+    await expect(mediaPrototype.play()).resolves.toBeUndefined();
 
     player.ngOnDestroy();
+
+    await expect(mediaPrototype.play()).rejects.toThrow('original play');
+
     host.ngOnDestroy();
   });
 });