Fix tool message handling, parallel image refs, error display, and UX polish

Remove tests, package.json, and test tooling

Split frontend script.js (5460 lines) into 8 focused modules

Refactor backend: extract async stream helper, direct tool registry, nudge_for_result via call_llm

Add HF Spaces YAML metadata to README

Reorganize project structure and update gitignore

v0.0