fix: update script entry point in pyproject.toml

refactor: flatten project structure to root for openenv validate compliance

fix: add root health check endpoint for 200 OK

fix: add Hugging Face Space metadata to README

fix: update internal app port to 7860 for full consistency

chore: optimize for Hugging Face Spaces and pass contest validation

feat: initial release for Scaler-Meta Hackathon with real-world datasets