Add Perplexity as AI provider

[giuseppe99barchetta]

I’d like to request the integration of Perplexity AI as an additional provider option for LLM Vision.
Perplexity offers advanced multimodal capabilities, including vision, and provides an accessible API (the Sonar API) that could be leveraged similarly to other existing AI backends.

This feature would open the door for improved multimodal workflows and broader model compatibility, making LLM Vision more flexible for users who already rely on Perplexity’s ecosystem.

If needed, I can help test or assist with integration details. The main API documentation is available at https://docs.perplexity.ai.

Thank you!