Fix: Improve error handling for Parent Chunk creation with better error messages and file path validation

app/routes.py

@@ -3708,7 +3708,15 @@ def create_file_parent_chunk(file_id):
             }), 500
         
     except Exception as e:
-        return jsonify({'error': f'Parent Chunk 생성 중 오류가 발생했습니다: {str(e)}'}), 500
+        import traceback
+        error_traceback = traceback.format_exc()
+        error_msg = str(e)
+        print(f"[Parent Chunk 생성] ❌ 예외 발생: {error_msg}")
+        print(f"[Parent Chunk 생성] Traceback:\n{error_traceback}")
+        return jsonify({
+            'error': f'Parent Chunk 생성 중 오류가 발생했습니다: {error_msg}',
+            'file_id': file_id
+        }), 500
 
 @main_bp.route('/api/files/<int:file_id>/process/parent-chunk', methods=['POST'])
 @login_required