feat: Prepare Zemailnator for Dokploy deployment

- Add highly optimized Dockerfile with Nginx and PHP-FPM 8.4
- Add docker-compose.yml configured with Redis and MariaDB 10.11
- Implement entrypoint.sh and supervisord.conf for background workers
- Refactor legacy IMAP scripts into scheduled Artisan Commands
- Secure app by removing old routes with hardcoded basic auth credentials
- Configure email attachments to use Laravel Storage instead of insecure public/tmp

app/Services/Payments/Providers/OxapayProvider.php

@@ -35,7 +35,7 @@ class OxapayProvider implements PaymentProviderContract
         $config = array_merge($dbConfig, $config);
 
         $this->config = $config;
-        $this->sandbox = $config['sandbox'] === "true" ?? false;
+        $this->sandbox = $config['sandbox'] === 'true' ?? false;
         $this->merchantApiKey = $this->sandbox ? ($config['sandbox_merchant_api_key'] ?? '') : ($config['merchant_api_key'] ?? '');
 
         $this->baseUrl = 'https://api.oxapay.com/v1';