feat: make incognito work

[barakplasma]

closes #24

Implements incognito mode, and removes the groq api key floating around various places. Aggresively defaults to localai in order to avoid sending people's files to groq accidentally.

I think it's a breaking change to require ollama, which is actually needed to support image categorization.

P.S. I'm having trouble with create_file_tree, I can't figure out how to pass the incognito request to that function.

Also I did not test this outside the /batch endpoint from the api. So someone else should test the electron app / watch util if they care about it.