`unbuild --stub` compatible with the browser

[webfansplz]

Describe the feature

Hi. Thanks for the awesome library. I like it and use unbuild stub mode in most of my projects. However, there is an issue that has forced me to remove it and use another tool instead temporarily.

When I was in the mono repo project, I had the Vite (client application) and some core packages. I had to fix the problem of jiti not working in the browser by configuring aliases in the Vite project. I see that we already have PR to solve this problem (#158). I believe that there are many users who encounter the same problem and it is very useful. Do we have any plans to release it soon? Thank you 🙏