Get Voice Preview

Return a short-lived signed GCS URL for the voice preview audio.

Result is cached in Redis (TTL controlled by the VOICE_PREVIEW_CACHE_TTL env var, default 10 min).

Args: voice_id: UUID of the voice whose preview should be fetched. x_api_key: Bearer API key from the x-api-key header. token_service: Injected token validation service. request: Raw FastAPI Request. version: API version extracted from the version request header.

Returns: VoicePreviewResponse: Signed URL pointing to the preview audio clip.