SecurePay BD payment method for this SMM panel (gateway "securepaybd").

1. Import db.sql (adds payment method id 69).
2. Upload the folder over your SMM install (patched core files included:
   app/controller/payment.php, app/controller/addfunds.php,
   admin/controller/settings/paymentMethods.php + sub files).
3. Admin > Settings > Payment Methods > Secure Pay BD > Edit:
   set your API Key (from SecurePay dashboard -> My Websites).

Notes:
- API endpoints point at the live gateway: https://pay.securepaybd.xyz
  /api/create and /api/verify (new SecurePay API).
- app/controller/payment.php routes the "securepaybd" callback to
  payment/securepaybd.php (the stock file pointed it at tuktakpay.php).
- methodLogo points at the SecurePay favicon image.