feat: switch email delivery from Resend to SMTP with libcurl integration

.env.example

@@ -5,8 +5,16 @@ MYSQL_PASSWORD=visione
 MYSQL_ROOT_PASSWORD=root
 MAILPIT_SMTP_PORT=1025
 MAILPIT_WEB_PORT=8025
-MAIL_PROVIDER=resend
-RESEND_API_BASE_URL=https://api.resend.com
-RESEND_API_KEY=
+
+MAIL_PROVIDER=smtp
+SMTP_HOST=127.0.0.1
+SMTP_PORT=1025
+SMTP_USERNAME=
+SMTP_PASSWORD=
+SMTP_USE_TLS=false
+SMTP_USE_STARTTLS=false
+SMTP_VERIFY_PEER=false
+SMTP_VERIFY_HOST=false
+
 MAIL_FROM=[email protected]
 CORS_ALLOWED_ORIGIN=http://localhost:3000