I've done a similar thing with https://github.com/DimitriGilbert/LiteChat/ but for features and not really UI ^^ you should give it a spin, it might give you ideas definitely going to try yours :)

edit: ooooh maaan... do you think you could add https://openrouter.ai/ key support please ? And for a bit of return on experience, you should absolutely use something like the vercel AI-SDK (or similar, i know there are more) to have support for many providers !

I created a tool I called parseArger to create/maintain bash scripts arguments/options/flags parsing code https://github.com/DimitriGilbert/parseArger It's heavily inspired by ArgBash (https://argbash.dev/) and uses parts of bashly (https://github.com/DannyBen/bashly/) which are very similar tools :) I hope that helps and please forgive the shameless plug...