feat(soniox): add TTS speed support

[rosetta-livekit-bot]

Summary

• Add Soniox TTS support to the JS plugin, including the Python source PR's speed option, [0.7, 1.3] validation range, runtime updates, and WebSocket request field.
• Export the TTS API and update the API report.
• Make pooled request cleanup deterministic across completion, provider errors, cancellation, abort, and retry.
• Add an exactly-once base SynthesizeStream completion hook so provider ownership spans the entire logical retry lifecycle.
• Add focused request-shaping, retry-output, cancellation, and lifecycle regression coverage with a patch changeset.

Source diff coverage

The source change from livekit/agents#6339 adds bounded Soniox TTS speed configuration. The JS port preserves its default, validation, update behavior, and initial WebSocket configuration field. JS-specific pooled WebSocket ownership and base-class retry behavior are covered by focused tests.

The Python implementation can pass through encoded formats. The JS TTS interface emits decoded AudioFrames, so this port explicitly accepts pcm_s16le and rejects unsupported formats instead of silently decoding them incorrectly.

Review fixes

• Reject non-finite speed values.
• Unregister chunked and streaming requests on normal and error paths.
• Settle cancellation locally when a provider never sends a terminal response.
• Remove settled requests from the owning TTS state exactly once after the full logical stream lifecycle.
• Replay cached streaming input on retry without conflating attempt cleanup with user cancellation.
• Preserve consumer-visible retry audio by leaving queue/output termination to the base lifecycle.
• Keep active retries owned so TTS.close() cancels and settles them before pooled socket shutdown.

Verification

• Soniox TTS/STT tests: 42 passed.
• Focused base and Soniox lifecycle tests: 32 passed.
• Repository build: 37/37 successful.
• Repository lint: 37/37 successful; unrelated existing warnings only.
• Repository format check: passed.
• Soniox API/type check: passed.
• Independent full-range correctness and architecture reviews: approved with no Critical or Important findings.

Cue voice E2E

Verified at exact PR head 0d19988a469404d6ed2327bcecd70f0164871ab8 in voice mode with a disclosed local protocol-compatible Soniox WebSocket boundary because SONIOX_API_KEY was unavailable.

• Session: sid_ec11dfb4a2b4.
• Input: Please verify the Soniox speaking speed.
• Completion predicate waited for final user transcription, AS_SPEAKING, the assistant conversation item, and return to AS_LISTENING/AS_IDLE; worker output independently reported playout completed without interruption.
• Result: resolved in 5,556 ms, exit code 0.
• Boundary captured speed: 1.3, 24 kHz pcm_s16le, 48,000 PCM bytes, terminal response, and socket cleanup; SHA-256 8b3e603753d90668c5890686a4fc550367eecfe243d4d709ae87d3a7afcb087f.
• Framework events included final STT, thinking, Soniox TTS usage with one second of audio, speaking, assistant output, and return to listening.
• Session WAV: stereo PCM16, 48 kHz, 16.114917 s, both channels nonzero, SHA-256 04a15610aa43d6ee8ee7537c254e1d6ff60add2452b62bb464022dba2fe2b398.
• Command WAV: stereo PCM16, 48 kHz, 5.599938 s, both channels nonzero, SHA-256 a477293786c1eba1ca0a90d8fb4740665f5faceb93971f71192e3882cbf100e0.
• events.jsonl SHA-256: aaaaf5aa43021a91888b04bdc0b36e3a7775c7abcf8223b8d09f813df091b871.
• result.json SHA-256: 12ef54ef40dee1946473821ee5eecc4481916bc42ac101b23afa7f2d62997ad1.

---

Ported from livekit/agents#6339

[changeset-bot]

🦋 Changeset detected

Latest commit: 0d19988

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

This PR includes changesets to release 36 packages

Name	Type
@livekit/agents-plugin-soniox	Patch
@livekit/agents	Patch
@livekit/agents-plugin-anam	Patch
@livekit/agents-plugin-anthropic	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-did	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-perplexity	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-tavus	Patch
@livekit/agents-plugin-trugen	Patch
@livekit/agents-plugin-xai	Patch
@livekit/agents-plugins-test	Patch

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