Bootstrap Ladill Link from QR Plus extract template.

config/mailbox.php

@@ -0,0 +1,9 @@
+<?php
+
+return [
+    // Consumer config for the platform Mailbox provisioning API (§4). Mail infra
+    // (Postfix/Dovecot via mail DB + pools) lives on the platform; this app
+    // provisions through the API. The user is identified by public_id.
+    'api_url' => env('MAILBOX_API_URL', 'https://ladill.com/api/mailboxes'),
+    'api_key' => env('MAILBOX_API_KEY_EMAIL'),
+];