Replace Azure Functions architecture with a modern FastAPI-based REST
API providing image, video, speech, and vision capabilities for General
Bots.
Key changes:
- Add FastAPI app with versioned API endpoints and OpenAPI docs
- Implement services for Stable Diffusion, Zeroscope, TTS/Whisper, BLIP2
- Add pydantic schemas for request/response validation
- Configure structured logging with structlog
- Support lazy model loading and GPU acceleration
- Update dependencies from Azure/TensorFlow stack to PyTorch/diffusers
