Remove unused Docusaurus starter assets

[hauptmedia]

Summary

• remove unreferenced Docusaurus starter images from static/img
• drop the stale Svg destructuring and unused featureSvg style from the homepage feature component
• silence the TypeScript 6 baseUrl deprecation so npm run typecheck remains green

Verification

• rg -n "docusaurus-social-card|docusaurus\.png|undraw_docusaurus|featureSvg|Svg" . -S -g "!node_modules/**" -g "!build/**" -g "!package-lock.json" returned no matches
• git diff --cached --check
• npm run typecheck
• npm run build succeeds; it still reports the pre-existing broken link/anchor warnings from main, which are addressed in Fix docs link checks and enforce quality gates #115