STEP 6 - Premium + SohojPayBD
1. Extract into the same folder as steps 2-5 (overwrite). config.php is not included.
2. phpMyAdmin -> Import schema_step6.sql ONCE.
3. Add your SohojPayBD details to config.php (recommended):
   define('SOHOJPAY_API_KEY',    'YOUR_API_KEY');
   define('SOHOJPAY_CREATE_URL', 'https://.../create-payment-endpoint');   // from your SohojPayBD docs / PollBD code
   define('SOHOJPAY_VERIFY_URL', 'https://.../verify-payment-endpoint');
   // only if your account differs from the defaults:
   // define('SOHOJPAY_KEY_HEADER', 'API-KEY');   // header that carries the key
   // define('SOHOJPAY_KEY_PREFIX', '');          // e.g. 'Bearer '
   // define('SOHOJPAY_FORMAT', 'json');          // or 'form'
   // define('SOHOJPAY_VERIFY_METHOD', 'POST');   // or 'GET'
   // define('SOHOJPAY_DEBUG', '1');              // logs gateway replies (not the key) to the PHP error_log
4. cPanel -> Cron Jobs (hourly):  /usr/local/bin/php /home/USER/public_html/cron/maintenance.php
