[codex] label navbar social links

[Sean-Kenneth-Doherty]

Summary

• Add explicit accessible labels to the navbar social links.
• Treat the visible social icons as decorative so the link name stays stable when text is hidden on small screens.
• Use a labeled <nav> landmark for the top link group.
• Fix the visible YouTube brand casing.

Why

The navbar hides its text labels at mobile widths. Explicit aria-label values keep each social link named consistently, while empty decorative image alts avoid duplicate names like youtube logo YouTube when the text is visible. A semantic nav landmark also gives assistive technology a named region for the top link group.

Validation

• pnpm build
• Confirmed built dist/index.html renders the labeled nav, navbar link aria-label attributes, decorative icon alt="" aria-hidden="true", and YouTube casing
• git diff --check

Related to #347.

[Sean-Kenneth-Doherty]

Fresh validation against the current PR head (2d1b8ef):

• the PR is scoped to src/components/Navbar.astro
• the top link group is now a nav landmark with aria-label="First Contributions links"
• all four social/project links have explicit aria-label values
• all four logo images are decorative with alt="" and aria-hidden="true"
• YouTube display casing is corrected from Youtube to YouTube
• GITHUB_TOKEN=$(gh auth token) pnpm build -> Astro build succeeded, 2 pages
• generated dist/index.html contains the nav landmark, 4 labeled links, 4 decorative logo images, and the YouTube casing change
• git diff --check origin/main...HEAD -> clean

Generated .astro/dist output was restored after validation.