feat(users): govern profiles and access

Normalize fixed profile fields, profile actions, and the five-column capability matrix for comments, uploads, and downloads.

src/Admin/ExtensionController.php

@@ -183,8 +183,8 @@ class ExtensionController extends ControllerBase {
                     'provider'          => (string) ($captcha['provider'] ?? ''),
                     'configured'        => !empty($captcha['configured']),
                     'scenes'            => $scenes,
-                    'download_required' => !empty($features['download_captcha']),
-                    'download_active'   => !empty($features['download_captcha']) && !empty($scenes['download']),
+                    'download_required' => !empty($scenes['download']),
+                    'download_active'   => !empty($scenes['download']),
                 ],
                 'content_audit'      => [
                     'enabled'    => !empty($services['audit']['enabled']),