Local models and other modification

[Tesla2000]

I am open to a discusion about some changes I added. Especially controversial can be removal of context length check which allows more flesibility in model choice and replacement of setting from config file with default which in my opinion makes it much more intuitive to use. It anything I would be pleased if you merge in change from repo_agent/utils/gitignore_checker.py which I believe is a bugfix. Previous behaviour caused indexing of gitignore files including .venv which shouldn't be the case