[plugins.json] Add cocoapods-cafswitcher

Please add the following entry to the `plugins.json` file:

```
{
"gem": "cocoapods-cafswitcher",
"name": "CocoaPods Cafswitcher",
"author": "handa",
"url": "https://github.com/WendStation/cocoapods-cafswitcher.git",
"description": "源码和二进制切换插件."
}
```

Open plugins.json and compare the requested entry with nearby plugin records, checking the existing formatting and required fields. Add the cocoapods-cafswitcher metadata exactly as specified, then validate that plugins.json remains valid JSON and includes the new plugin.

Written by the indexing model from the issue text.