fix(comments): align image upload with Zibll

Unify comment image upload settings, REST permissions, preview, progress,
and response handling while removing obsolete compatibility paths.

assets/admin/src/schema/sections/post-list/comment.js

@@ -15,6 +15,7 @@ export const commentSchema = {
     comment_edit_window: 10,
     comment_code: true,
     comment_img: true,
+    comment_upload_img: false,
     comment_link: false,
     comment_like_s: true,
     comment_hot_threshold: 10,