[FEATURE] Multi-model LLM support

[arvinder004]

---

name: "Feature: Multi-model LLM support"
about: Allow switching between different LLM backends (Mistral, LLaMA3, GPT, etc.)
title: "[FEATURE] Multi-model LLM support"
labels: enhancement, AI/NLP

Summary

The system currently hardcodes "model": "mistral" in src/llm.py. There is no way to configure or switch the LLM model at runtime or via environment variables.

Problem

• Users on different hardware may not be able to run Mistral locally.
• There is no support for cloud-based models (OpenAI, Anthropic) or other Ollama-hosted models (LLaMA3, Phi3, Gemma).
• Changing the model requires editing source code directly.

Proposed Solution

• Add a model parameter to the LLM class constructor.
• Read the model name from an environment variable LLM_MODEL with mistral as default.
• Expose the model selection via the API request schema (FormFill).
• Document supported models in README.

Acceptance Criteria

• LLM class accepts a model parameter
• Model defaults to LLM_MODEL env var, falling back to mistral
• API schema exposes optional model field
• Works with at least 2 different Ollama models

Additional Context

Relevant file: src/llm.py, api/schemas/forms.py, src/file_manipulator.py

[marcvergees]

Very good idea. We'll test it out before merging it.

[arvinder004]

Yeah sure.

[arvinder004]

@marcvergees I wanted to suggest some more ideas. But I have already submitted the proposal. Can I raise some issues and tag you over there?

It would be great if we can connect and discuss over these. I have some interesting and important feature updates for FireForm.

Looking forward for contributing to this project.

[marcvergees]

Hi @arvinder004, we wanna merge your PR #257, but it looks like is outdated with what we have. Are you still interested to update it so that we can merge it? Thank you.

[arvinder004]

I wanted to connect with you previously regarding this, but you did not responded. I think I would have some time for this. By the time let me know what changes apart from above you want in this.

[marcvergees]

Hi @arvinder004, that's good for now. If you wanna go further away, you'll se 3 new opened issues, with nobody assigned, in case you wanna work on it.