Enhance serve.py with fine-tuning job management, including job creation, status tracking, and training process in a separate thread. Update serve_test.py to include a test for fine-tuning functionality. Modify .gitignore to exclude model files. This update improves model training capabilities and API integration.

Add serve_test.py for testing chat completion functionality with the OpenAI client. Update serve.py to use FastModel for improved performance and adjust input handling for optional image processing. Include debugging output for better error tracking.