[Feature] Prettier

[greg5green]

Adds Prettier to standardize code style across the project and enforces it automatically before every commit via Husky.

What changed?

• Prettier (prettier, .prettierrc) — configured with singleQuote: true and arrowParens: always, targeting .js, .scss, and .html files
• Husky (.husky/pre-commit) — runs prettier --check before every commit, blocking unformatted code from being committed
• New scripts — npm run format (auto-fix) and npm run format:check (check only)
• Formatted files — static/js/httpconfig.js, static/scss/httpconfig.scss, static/html/httpconfig.html, and test/httpconfig.test.js reformatted to match config