Move service favicon to domain row

[arjunkomath]

Summary

• remove the favicon from beside the service name
• use the favicon instead of the globe icon in the public-domain row
• preserve the existing favicon lookup, size, and error handling

Checks

• pnpm exec oxfmt --check components/service/service-canvas.tsx
• ./node_modules/.bin/tsc --noEmit
• pnpm lint (passes with 7 existing warnings in unrelated files)

[github-actions]

React Doctor found no new issues. 🎉

_{Reviewed by React Doctor for commit eb9010a.}