Pin langchain >=0.2.0,<0.3.0 to preserve old import paths; revert utils.py import

Author: anas-elghafari

backend/pyproject.toml

@@ -50,7 +50,7 @@ dependencies = [
     "transformers",
     "python-dotenv",
     "qdrant-client",
-    "langchain",
+    "langchain >=0.2.0,<0.3.0",
     "langchain_openai",
     "pydantic",
     "langchain_qdrant",

backend/src/mapping_generation/utils.py

@@ -9,7 +9,7 @@
 # import psutil
 import pandas as pd
 from json_repair import repair_json
-from langchain_core.documents import Document
+from langchain.schema import Document
 from simstring.database.dict import DictDatabase
 from simstring.feature_extractor.character_ngram import CharacterNgramFeatureExtractor
 from simstring.measure.cosine import CosineMeasure