Wider speed range for Flux TTS

Flux TTS speed now runs from 0.5 to 1.5 in 0.05 increments, up from 0.85–1.15. The default stays 1.0, and every previously accepted value still works.

The wider range applies everywhere speed is accepted on Flux TTS: the /v2/speak streaming WebSocket (at connection and mid-session with Configure), the /v2/speak batch REST endpoint, and agent.speak.provider.speed in Voice Agent sessions running provider.version v2. A value outside the range is still rejected with SPEED_OUT_OF_RANGE, and one off the 0.05 increment with SPEED_INCREMENT_INVALID.

Aura speed is unchanged at 0.7–1.5.

For details, see Getting Started with Flux TTS, Client Messages, and TTS Models.