Fix security and quality dependency vulnerabilities in website

[danbaruka]

Summary

Open Dependabot / npm audit findings in website/ need remediation for security and dependency quality.

Current signal

• npm audit reports 149 vulnerabilities (2 low, 2 moderate, 144 high, 1 critical)
• Open Dependabot packages include: body-parser, brace-expansion, dompurify, fast-uri, http-proxy-middleware, js-yaml, postcss, shell-quote, svgo, undici, webpack-dev-server, websocket-driver

Goals

1. Update direct and transitive dependencies (via npm overrides/resolutions where needed) to patched versions
2. Clear high/critical audit findings where fixes exist
3. Keep Docusaurus site build healthy (npm run build)
4. Prefer minimal, reviewable dependency-only changes

Acceptance criteria

• Security advisories addressed or documented if blocked by upstream
• npm audit improved (ideally no high/critical remaining when fix available)
• website production build succeeds
• PR linked to this issue

Notes

Existing overrides / resolutions in website/package.json are present but several pinned versions are still within vulnerable ranges and need bumping.