Update model from llama-3.1-70b-versatile to openai/gpt-oss-120b

Revert Gradio back to version 4.0.0

Update Gradio to version 5.0.0 to fix security vulnerabilities

Fix configuration: Use Gradio SDK and remove README.md from gitignore

Clean repository: Keep only essential files with proper HF Space README

Initial commit: Story Generation Agents app