请求提供下xhofe/ddddocr_server:main的dockerfile，源码，看下/ocr/file/json这个接口怎么实现的

### Please make sure of the following things

- [x] I have read the [documentation](https://alist.nn.ci).
- [x] I'm sure there are no duplicate issues or discussions.
- [x] I'm sure this feature is not implemented.
- [x] I'm sure it's a reasonable and popular requirement.

### Description of the feature / 需求描述

xhofe/ddddocr_server:main 这个镜像有点大，nodejs/rust重写，但是需要复现/ocr/file/json接口，需要了解下内部逻辑
故，期望提供下源码参考下..

或者alist这边是如何提交的，提交body结构

### Suggested solution / 实现思路

_No response_

### Additional context / 附件

_No response_