feat: add ModelsLab chat provider

[adhikjoshi]

Summary

Adds ModelsLab as an OpenAI-compatible chat provider for aisuite.

ModelsLab provides uncensored chat via their OpenAI-compatible endpoint at https://modelslab.com/api/uncensored-chat/v1.

Usage

export MODELSLAB_API_KEY=your_key

import aisuite as ai

client = ai.Client()
messages = [{"role": "user", "content": "Hello!"}]
response = client.chat.completions.create(
    model="modelslab:meta-llama/Meta-Llama-3-8B-Instruct",
    messages=messages,
)

Implementation

• Uses the official openai Python client with custom base_url
• Follows the same pattern as inception_provider.py (OpenAI-compatible providers)
• Requires MODELSLAB_API_KEY env var or api_key in config

Files Changed

• aisuite/providers/modelslab_provider.py — new provider (59 lines)

API Details

• Base URL: https://modelslab.com/api/uncensored-chat/v1
• Auth: api_key in client config
• Models: Any model supported by ModelsLab's uncensored chat endpoint
• Docs: https://docs.modelslab.com