Add a "library" of files that the model can look into for extra context

Each profile would have its a limited amount of slots for files that models can retrieve on-demand.

For example, I have a profile for job search and often have to upload my CV into every thread when I wanna have an LLM write me cover letters. Would be nicer if the LLMs could simply retrieve my CV from a stash of files that I give it access to.