refactor(modules): extract castopod parts into a modules/ folder for a scalable HMVC structure

- create Admin, Analytics, Auth, Fediverse and Install modules in the root modules/ folder
- rename
ActivityPub to Fediverse

modules/Install/Config/Install.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Modules\Install\Config;
+
+use CodeIgniter\Config\BaseConfig;
+
+class Install extends BaseConfig
+{
+    /**
+     * --------------------------------------------------------------------------
+     * Install gateway
+     * --------------------------------------------------------------------------
+     * Defines a base route for instance installation
+     */
+    public string $gateway = 'cp-install';
+}