What problem does this feature solve?

I currently use vite v7, and Rollup's output.sourcemapFileNames option to put all sourcemaps in a separate directory. I'd like to have the same funxtionality in vite v8 through rolldown, especially that I haven't seen any mentions / reasoning for not including this option.

If you think it's a good candidate for a first issue, I'd love to have my shot at implementing it. Thanks!

What does the proposed API look like?

Same as in rollup