修改了从数据库中查找取费表和工程量表，新加了一个树状搜索总结搜索引擎

backend/app/engine/engine.py

@@ -86,7 +86,7 @@ def create_summary_query_engine(index, top_k=3, use_reranker=False, filters=None
     return summary_query_engine
 
 # Create a query engine
-def create_query_engine(index, top_k=3, use_reranker=False, filters=None):
+def create_query_engine(index, top_k=3, use_reranker=False, filters=None, response_mode=None):
     # 创建向量检索查询工具
     postprocess = None
     if use_reranker:
@@ -103,6 +103,7 @@ def create_query_engine(index, top_k=3, use_reranker=False, filters=None):
         node_postprocessors=postprocess,
         use_async=True,
         streaming=True,
+        ResponseMode = response_mode
     )
 
     return query_engine