fix: restore full Gnaroshi site identity

[Gnaroshi]

Summary

• restore the approved full-face Gnaroshi mascot across favicon, touch, manifest, header, and footer assets
• keep pixel canopy artwork limited to application role icons
• add media and browser regressions that reject an ears-only primary website mark

Verification

• npm run media:check
• npm run check
• npm run build
• npx playwright test tests/e2e/media.spec.ts --project=chromium
• npm run test:a11y
• visual inspection at 1440x1000 and 390x844 in light and dark themes