Initial commit: clean project structure

- Backend: FastAPI + SQLAlchemy + Celery (Python 3.11+)
- Frontend: Vue 3 + TypeScript + Pinia + Tailwind
- Admin Frontend: separate Vue 3 app for management
- Docker Compose: 9 services orchestration
- Specs: design prototypes, memory system PRD, product roadmap

Cleanup performed:
- Removed temporary debug scripts from backend root
- Removed deprecated admin_app.py (embedded UI)
- Removed duplicate docs from admin-frontend
- Updated .gitignore for Vite cache and egg-info

backend/app/services/adapters/tts/__init__.py

@@ -0,0 +1,5 @@
+"""TTS 语音合成适配器。"""
+
+from app.services.adapters.tts import edge_tts as _tts_edge_tts_adapter  # noqa: F401
+from app.services.adapters.tts import elevenlabs as _tts_elevenlabs_adapter  # noqa: F401
+from app.services.adapters.tts import minimax as _tts_minimax_adapter  # noqa: F401