[fancy_pantser]

No fine-tuning is necessary. You can use something reasonably good at RAG that's small enough to run locally like the Command-R model run by Ollama and a small embedding model like Nomic. There are dozens of simple interfaces that will let you import files to create a RAG knowledgebase to interact with as you describe, AnythingLLM is a popular one. Just point it at your locally-running LLM or tell them to download one using the interface. Behind the scenes they store everything in LanceDB or similar and perform the searching for you when you submit a prompt in the simple chat interface.