WeChat Official Account API Publishing

Use the Official Account's AppID/AppSecret to directly call WeChat's API to publish a rich-text article: upload the cover image, convert images in the article body to WeChat image URLs automatically, create a draft, and then choose to either mass-send to followers or publish only to the Official Account's homepage, based on whether to push to followers, and wait for the publication result. Only enterprise-verified Official Accounts are supported. Before running, you must add your machine's public IP to the IP whitelist in the Official Account backend (a clear error will be shown if the IP is incorrect).