Extract the voice-cloning feature from jamiepine/voicebox (Qwen3-TTS Base
engine) into a small standalone app: FastAPI backend (engine.py + app.py)
wrapping create_voice_clone_prompt/generate_voice_clone, and a single-page
UI (upload or mic-record a reference clip + transcript -> synthesize any
text in that voice). Supports 10 languages incl. Korean; model loads lazily
and downloads on first use.
