Potential fix for code scanning alert no. 3: Information exposure through an exception

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: GitTimeraider

app.py

@@ -540,7 +540,8 @@ def test_backup_with_context():
         result = test_backup_with_context()
         return jsonify({'success': True, 'message': result})
     except Exception as e:
-        return jsonify({'success': False, 'error': str(e)}), 500
+        logger.error(f"Error in /api/test-backup endpoint for repository {repo_id}: {e}", exc_info=True)
+        return jsonify({'success': False, 'error': 'An internal error occurred.'}), 500
 
 @app.route('/api/theme', methods=['POST'])
 @login_required