Set body background-color to --bg_secondary so areas outside
the halftone main element match instead of showing white.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Move Vue app from nginx/vue/ to top-level vue/ with its own Dockerfile,
update docker-compose configs and nginx proxy to serve from the new
container, and add initial Rust WASM crate (stp_wasm). Also fix .gitignore
to exclude Rust target/ directories.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>