Fix multi-image selection when mime type is missing

resources/js/guest-v2/__tests__/UploadScreen.test.tsx

@@ -147,4 +147,20 @@ describe('UploadScreen', () => {
     });
     expect(addToQueueMock).not.toHaveBeenCalled();
   });
+
+  it('accepts image files with empty mime type when extension is valid', async () => {
+    const { container } = render(
+      <EventDataProvider token="token">
+        <UploadScreen />
+      </EventDataProvider>
+    );
+
+    const input = container.querySelector('input[type="file"]') as HTMLInputElement;
+    const file = new File(['rawdata'], 'from-library.jpg', { type: '' });
+
+    fireEvent.change(input, { target: { files: [file] } });
+
+    expect(await screen.findByLabelText('Remove photo')).toBeInTheDocument();
+    expect(screen.getByText('{count} photos selected')).toBeInTheDocument();
+  });
 });