/**:
  ros__parameters:
    tts_service:
      voice_model_path: "/models/piper/en_US-lessac-medium.onnx"
      sample_rate: 22050
      speed: 1.0              # Normal playback speed
      pitch: 1.0              # Normal pitch
      volume: 0.8             # 0–1.0 (safety: reduced from 1.0)
      audio_device: "Jabra"   # ALSA device name or alias
      queue_max_size: 16      # Max queued TTS requests
      autoplay: true          # Auto-play TTS on startup
