feat(users): govern profiles and access

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

src/Settings/AuthReader.php

@@ -17,7 +17,12 @@ trait AuthReader {
 
     /** 是否要求注册用户才能评论 */
     public static function comment_requires_registration(): bool {
-        return !empty(self::get_value('comment_require_login', false)) && self::comment_enabled();
+        if (!self::comment_enabled()) {
+            return true;
+        }
+
+        $user_id = get_current_user_id();
+        return !class_exists(Capabilities::class) || !Capabilities::user_can('comment_add', $user_id);
     }
 
     /** 是否允许注册 */