Update agent_langchain.py

agent_langchain.py

@@ -99,8 +99,9 @@ CHROMA_PATH = "/tmp/chroma"  # Persistent path in Space
 COLLECTION_NAME = "knowledge_base"
 
 kb_collection = None  # Global placeholder, initialized via /setup
-embedding_func = embedding_functions.SentenceTransformerEmbeddingFunction(
-    model_name="sentence-transformers/all-MiniLM-L6-v2"
+embedding_func = embedding_functions.OnnxMiniLM_L6_V2(
+    model_name="all-MiniLM-L6-v2",
+    download_path="/tmp/onnx_models"  # <-- writable path
 )
 kb_lock = threading.Lock()  # Ensure thread-safe updates