feat: make media inspection progressive

tests/unit/components/quick-convert.test.tsx

@@ -16,6 +16,66 @@ import type { UserExportPreset } from '../../../src/presets';
 afterEach(cleanup);
 
 describe('QuickConvert', () => {
+  it('keeps an uninspected source usable and requests stream detection with export', async () => {
+    const user = userEvent.setup();
+    const onInspect = vi.fn();
+    const onExport = vi.fn<(configuration: QuickExportConfiguration) => void>();
+    const file = new File(['media'], 'lecture.mp4', { type: 'video/mp4' });
+    const asset: ImportedMediaAsset = {
+      id: 'asset-basic',
+      file,
+      objectUrl: 'blob:asset-basic',
+      phase: 'idle',
+      browserMetadata: {
+        source: 'browser',
+        file: {
+          name: file.name,
+          sizeBytes: file.size,
+          declaredMimeType: file.type,
+          inferredMimeType: file.type,
+          lastModified: file.lastModified,
+        },
+        kind: 'video',
+        durationSeconds: 2_622.48,
+        width: 640,
+        height: 480,
+        hasVideo: true,
+      },
+    };
+
+    render(
+      <QuickConvert
+        asset={asset}
+        engineState={readyEngine()}
+        busy={false}
+        onInspect={onInspect}
+        onExport={onExport}
+      />
+    );
+
+    expect(screen.getByText(/43:42\.48/u)).toBeVisible();
+    expect(screen.getByText('Ready to play')).toBeVisible();
+    await user.click(
+      screen.getByRole('button', { name: 'Inspect details now' })
+    );
+    expect(onInspect).toHaveBeenCalledOnce();
+
+    await user.click(screen.getByRole('button', { name: 'Inspect & convert' }));
+    expect(onExport).toHaveBeenCalledWith(
+      expect.objectContaining({
+        operation: 'convert',
+        selectDetectedStreams: true,
+        streamSelection: {
+          video: [],
+          audio: [],
+          subtitles: [],
+          attachments: [],
+          data: [],
+        },
+      })
+    );
+  });
+
   it('labels a submission honestly when another operation is active', () => {
     render(
       <QuickConvert