fix: handle invalid qr share tokens without 500 (#2597)

packages/app-tests/e2e/pdf-viewer/pdf-viewer.spec.ts

@@ -202,6 +202,15 @@ test.describe('PDF Viewer Rendering', () => {
       await page.getByRole('button', { name: /Page 2/ }).click();
       await expect(page.locator(PDF_PAGE_SELECTOR).first()).toBeVisible({ timeout: 30_000 });
     });
+
+    test('should not return 500 for invalid QR share token', async ({ page }) => {
+      const response = await page.request.get('/share/qr_invalid_token_for_regression_check', {
+        maxRedirects: 0,
+      });
+
+      expect(response.status()).toBe(302);
+      expect(response.headers().location).toBe('/');
+    });
   });
 
   test.describe('Embed Pages', () => {