FastMCP 3.0 Streamable HTTP server exposing Piper (Wyoming/Docker),
Kokoro (ONNX), and Orpheus (Ollama+SNAC) as MCP tools. Includes a
FIFO speech queue so concurrent agents don't talk over each other —
waiting callers get queue position updates via ctx.info().
Tools: speak, generate_audio, list_voices, list_engines
Resource: audio://recent
