add support for persisted db

app.py

@@ -1,20 +1,12 @@
 import os
-# from dotenv import load_dotenv
 import gradio as gr
 from sqlalchemy import text
 from smolagents import tool, CodeAgent, HfApiModel
 import spaces
 
-# Import database
+# Import the persistent database
 from database import engine, receipts
 
-# Load Hugging Face API token
-# load_dotenv(override=True)
-# hf_token = os.getenv("HF_TOKEN")
-
-# if not hf_token:
-#    raise ValueError("HF_TOKEN environment variable is not set.")
-
 @tool
 def sql_engine(query: str) -> str:
     """
@@ -25,7 +17,6 @@ def sql_engine(query: str) -> str:
         - customer_name: VARCHAR(16)
         - price: FLOAT
         - tip: FLOAT
-
     Args:
         query: The SQL query to execute.