Add baseten plugin

[pvkadam]

Description

Added Baseten plugin for LiveKit Agents, enabling integration with Baseten-hosted AI models. Provides LLM (via OpenAI-compatible API), streaming STT (with WebSocket and VAD), and TTS services for building voice AI applications in TypeScript/Node.js.

Changes Made

• New Plugin: plugins/baseten/
  • llm.ts - LLM using Baseten's OpenAI-compatible endpoint
  • stt.ts - Streaming STT with WebSocket, VAD, and partial/final transcripts
  • tts.ts - Streaming TTS audio synthesis
  • types.ts - TypeScript interfaces for all options
  • index.ts - Plugin registration and exports
• Test files, README, and documentation

Pre-Review Checklist

• Build passes: All builds (lint, typecheck, tests) pass locally
• AI-generated code reviewed: Removed unnecessary comments and ensured code quality
• Changes explained: All changes are properly documented and justified above
• Scope appropriate: All changes relate to the PR title, or explanations provided for why they're included
• Video demo: A small video demo showing changes works as expected and did not break any existing functionality using Agent Playground (if applicable)

Testing

• Automated tests added/updated (if applicable)
• All tests pass
• Make sure both restaurant_agent.ts and realtime_agent.ts work properly (for major changes)

Additional Notes

---

Note to reviewers: Please ensure the pre-review checklist is completed before starting your review.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 804edab

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[CLAassistant]

All committers have signed the CLA.

[toubatbrian]

Hey @pvkadam, could you record a small demo showcasing the new plugin in agent playground? Thanks!