added db import

app/db.py

@@ -16,9 +16,11 @@ import os
 import pathlib
 import json
 import duckdb
+import pandas as pd  # ✅ CRITICAL: For type hints and DataFrame handling
 from typing import Any, Dict, List, Optional
 from datetime import datetime
 from contextlib import contextmanager
+from fastapi import HTTPException 
 
 # ==================== CONFIGURATION ==================== #
 DB_DIR = pathlib.Path("./data/duckdb")