feat request: integrate republic to use codex

[bxb100]

I tested https://github.com/bubbuild/republic, and it seems to be a valid solution for using various AI providers for translation

And most importantly, it supports Codex auth¹, so we can use GPT-5.4 at a low cost.

Please forgive me as I am not familiar with Python, so I am unable to submit a PR.

I would appreciate it if someone could integrate this with book_marker.

Thanks.

Footnotes

1. https://github.com/bubbuild/republic/blob/main/examples/06_openai_codex_oauth.py ↩

[yihong0618]

of course patch welcome, sorry for late reply
and will replease a version this week