Update the data-upload attribute on the upload button in the admin background
configuration page to correctly reference 'admin_background' instead of
'site_ico', ensuring the button functions as intended when uploading a new
background image.
Due to the recommendation for better performance and user experience,
the default editor in both configuration files and view templates has been
switched from ueditor to wangEditor. The code changes reflect this update by
marking ueditor as '(不建议使用)' (not recommended) and WangEditor as
'(推荐使用)' (recommended). Additionally, the relevant controller file has
been updated to ensure that the correct default editor is loaded based on
the new configuration setting.
