Merge branch 'feature/luojunhui/2025-09-25-improve-nlp-task-prompt' of Server/rag_server into master

requirements.txt

@@ -21,4 +21,7 @@ tiktoken==0.11.0
 uvloop==0.21.0
 elasticsearch==8.17.2
 scikit-learn==1.7.2
-neo4j==5.28.2
+neo4j==5.28.2
+langchain==0.3.27
+langchain-core==0.3.76
+langchain-text-splitters==0.3.11