Fix startup crash by importing pyotp lazily inside function

backend/app/services/auto_login_service.py

@@ -1,10 +1,8 @@
-import json
 import threading
 import time
 from datetime import datetime, timedelta, timezone
 from urllib.parse import parse_qs, urlparse
 
-import pyotp
 import requests
 
 from app.services.crypto_service import decrypt_value, encrypt_value
@@ -200,6 +198,7 @@ def _perform_zerodha_login(
     request_id = login_data["data"]["request_id"]
 
     # Step 2: TOTP — don't follow redirect automatically
+    import pyotp  # imported here so missing package doesn't crash startup
     totp_value = pyotp.TOTP(totp_secret).now()
     twofa_resp = session.post(
         KITE_TWOFA_ENDPOINT,