Add Perplexity plugin with Responses support

[rosetta-livekit-bot]

Summary

• add dedicated @livekit/agents-plugin-perplexity package mirroring the Python plugin structure
• support Perplexity chat completions via LLM and Agent API/Responses via responses.LLM
• configure Perplexity base URLs, PERPLEXITY_API_KEY fallback, HTTP Responses transport, and X-Pplx-Integration attribution headers
• add README usage, API report, lockfile entry, and a patch changeset

Tests

• pnpm --filter @livekit/agents-plugin-perplexity build
• pnpm --filter @livekit/agents-plugin-perplexity lint
• pnpm vitest run plugins/perplexity/src/llm.test.ts plugins/perplexity/src/responses/llm.test.ts
• pnpm --filter @livekit/agents-plugin-perplexity api:check

[changeset-bot]

🦋 Changeset detected

Latest commit: 25275f6

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 32 packages

Name	Type
@livekit/agents-plugin-perplexity	Patch
@livekit/agents	Patch
@livekit/agents-plugin-anam	Patch
@livekit/agents-plugin-assemblyai	Patch
@livekit/agents-plugin-baseten	Patch
@livekit/agents-plugin-bey	Patch
@livekit/agents-plugin-cartesia	Patch
@livekit/agents-plugin-cerebras	Patch
@livekit/agents-plugin-deepgram	Patch
@livekit/agents-plugin-elevenlabs	Patch
@livekit/agents-plugin-fishaudio	Patch
@livekit/agents-plugin-google	Patch
@livekit/agents-plugin-hedra	Patch
@livekit/agents-plugin-hume	Patch
@livekit/agents-plugin-inworld	Patch
@livekit/agents-plugin-lemonslice	Patch
@livekit/agents-plugin-liveavatar	Patch
@livekit/agents-plugin-livekit	Patch
@livekit/agents-plugin-minimax	Patch
@livekit/agents-plugin-mistral	Patch
@livekit/agents-plugin-mistralai	Patch
@livekit/agents-plugin-neuphonic	Patch
@livekit/agents-plugin-openai	Patch
@livekit/agents-plugin-phonic	Patch
@livekit/agents-plugin-resemble	Patch
@livekit/agents-plugin-rime	Patch
@livekit/agents-plugin-runway	Patch
@livekit/agents-plugin-sarvam	Patch
@livekit/agents-plugin-silero	Patch
@livekit/agents-plugin-trugen	Patch
@livekit/agents-plugin-xai	Patch
@livekit/agents-plugins-test	Patch

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 4 additional findings.