Is your feature request related to a problem? Please describe.

Perplexity models are currently not supported in the Phoenix Playground. As a result, it is not possible to trace, replay, or interactively experiment with Perplexity models like sonar, sonar-pro, sonar-reasoning-pro, and sonar-deep-research inside the playground.

These models are widely used and are considered SOTA for search, reasoning, and deep research workflows. The lack of Playground support makes it harder to debug prompts, inspect traces, and iterate on applications that already use Perplexity in production.

Describe the solution you'd like

Add Perplexity as a first-class provider in the Phoenix Playground, similar to how other OpenAI-compatible providers like DeepSeek and xAI are integrated.

This would involve:

• Adding a backend provider for Perplexity
• Implementing the corresponding client integration
• Adding frontend provider handling so Perplexity models are selectable and usable in the Playground UI

This would enable seamless tracing, prompt replay, and experimentation with Perplexity models directly within Phoenix, aligning the experience with other supported providers.