fix(admin): replicate reference comment settings page 1:1

- Rewrite post_list/comment schema (PHP + JS) with the reference theme's
  field set, order, defaults and dependencies; smilie, comment location
  and quick-reply fields excluded
- Map PostDisplay::get_comment_display_settings() to the new keys without
  legacy fallback: close_comments, comment_paginate_type (ajax_lists),
  user_edit_comment master switch, WP comment_order for sorting
- Wire comment_box_hide visibility gate (signin / vip / vip_2 / auth)
- Drop dead comment settings (order/per_page/depth/avatar/hot threshold/
  empty text/city), the dead post_close_comments field, and city readers
  now fully owned by the IP-geo extension
- Add comment settings reference contract test

src/Core/CommentActions.php

@@ -163,7 +163,7 @@ class CommentActions {
     }
 
     /**
-     * Permission: can edit? (author within configured window, or moderator)
+     * Permission: can edit? (author with 允许用户编辑评论 on, or moderator)
      */
     public function check_edit_permission(\WP_REST_Request $request): bool {
         if (!is_user_logged_in()) return false;