move import os to top

src/legisqa_local/core/vectorstore.py

@@ -1,6 +1,7 @@
 """Vector store operations for LegisQA"""
 
 import logging
+import os
 import streamlit as st
 from langchain_chroma import Chroma
 from legisqa_local.core.embeddings import load_embeddings
@@ -30,7 +31,6 @@ def load_vectorstore():
             logger.info(f"   {key}={value}")
     
     # Check if the directory actually exists
-    import os
     if not os.path.exists(config["persist_directory"]):
         logger.error(f"❌ ChromaDB directory does not exist: {config['persist_directory']}")
         # Try to find the correct path