test(playback): verify recommendation capability guards

apps/web-e2e/src/dash-clearkey.e2e.ts

@@ -150,4 +150,13 @@ test('@web @m3u @dash unsupported DRM shows the encryption diagnostic', async ({
     const banner = page.locator('[data-test-id="playback-diagnostic-banner"]');
     await expect(banner).toBeVisible({ timeout: 15_000 });
     await expect(banner).toContainText(/encrypted or DRM-protected/i);
+    await expect(
+        banner.locator('[data-test-id="playback-fallback-mpv"]')
+    ).toHaveCount(0);
+    await expect(
+        banner.locator('[data-test-id="playback-fallback-vlc"]')
+    ).toHaveCount(0);
+    await expect(
+        banner.locator('[data-test-id^="playback-recommendation-"]')
+    ).toHaveCount(0);
 });

apps/web-e2e/src/fixtures/playback/unsupported.mkv

@@ -0,0 +1 @@
+This fixture intentionally declares Matroska without playable media bytes.