Improve: API docs experience

[ShadowArcanist]

https://fumadocs.vercel.app/docs/openapi way better layout + color choice for API docs in both light and dark mode.

[ShadowArcanist]

@justserdar I think this one is a very big task, so I didn't add it to any cycle. we can work in this slowly

[justserdar]

I agree, we made progress with the new collapsible sidebar in the open api section of the docs. The next step would a full width layout for that section like fumadocs reference. Should be doable w/o too much time, I recommend we just use a custom layout wrapping those pages.