AI support more file import types

[luke-quadratic]

This is a short-cut to supporting a large number of file types.

Allow user inputs for more files - PDFs, .txt, etc that AI can extract the relevant information from the file and input into the sheet. The models are already built to be extremely capable at this use-case, we just need to support it on our end and sufficiently instruct the AI how to take a summary and convert it to sheet structure.