Strip YAML frontmatter to only essential fields

Restore YAML frontmatter in README.md (required for HF Spaces config)

Show full prompt text on sample buttons; add .huggingface/metadata; add HF badge to README

Fix YAML metadata: use literal emoji instead of shortcode

Add HF Spaces YAML metadata to README

Add requirements.txt and update README install instructions

Initial commit: self-correcting agentic coding sandbox

initial commit