Refactor app.py to improve dataset metadata retrieval and enhance Gradio interface with better prompt field validation and export options

Refactor model loading: replace vllm with transformers for improved model handling and update requirements.txt

Refactor device detection: replace cupy with torch for CUDA availability check in app.py and eval_llm.py; update requirements.txt

Enhance device management: add get_device function for CUDA detection and update model loading in app.py and eval_llm.py

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