In lieu of raising the character limit it would be great to allow uploads for code mode, perhaps file size limited so we could perhaps use the Assistant to analyze a full source code file. There could be a file size limit in place to prevent uploading something too big that would cost too much money. FIle types could also be limited to common source code extensions.
I think this could be a great way to easily analyze source code. For example when working with a full HTML page I may be having a problem with something that I need to give the AI more context to solve. Being able to upload a file would be a great way to make this easier.
