[Feature]: 今日头条粘贴的图片为网络链接时，自动转成今日头条的图片链接

### Problem Description / 问题描述

今日头条里面的图片如果是网络链接，就无法进行提交。

### Proposed Solution / 建议的解决方案

无，不知道怎么解决

### Alternatives Considered / 考虑过的替代方案

_No response_

### Feature Type / 功能类型

New platform support / 新平台支持

### Additional Context / 补充信息

_No response_

### Implementation / 实现意愿

- [ ] I'm willing to submit a PR for this feature / 我愿意为此功能提交 PR
- [ ] I'd prefer to wait for community implementation / 我希望等待社区的实现

Start by locating the browser extension entry point that handles pasting images and the existing integrations for content platforms. Reproduce the 今日头条 case with an image supplied as a network URL, then trace how other platforms submit images. Done means pasted network images are converted to a 今日头条-compatible image link and the article can be submitted successfully.

Written by the indexing model from the issue text.