fix: update community social links and X icon

[sb123sb123]

Closes #1016

Summary

• Point the footer's X/Twitter and Instagram links to Reframe's accounts.
• Replace the deprecated Twitter glyph with the X mark and give it an X (Twitter) accessible name.
• Add a regression test for the destinations, accessible name, and safe new-tab attributes.

Validation

• bun run lint — passed.
• bunx tsc --noEmit — passed.
• bun run build — passed.
• bun run test -- --run src/components/__tests__/Footer.test.tsx — 1 passed.
• Desktop and 375px mobile browser checks passed; no browser errors.
• Full bun run test -- --run — 107 passed, 8 failed in untouched tests: duplicate Vitest imports in src/lib/exportEstimate.test.ts, unavailable localStorage in the existing persistence and theme tests, and an existing useVideoEditor assertion failure.

Screen recording

reframe-footer.webm

[netlify]

👷 Deploy request for reframe-os pending review.

Visit the deploys page to approve it

Name	Link
🔨 Latest commit	1eb6230

[github-actions]

👋 Thanks for your PR, @sb123sb123!

Welcome to Reframe — a browser-based video editor built for everyone 🎬

What happens next

1. 🤖 Automated checks — build & TypeScript typecheck will run automatically
2. ✅ Vercel preview — a preview deployment will be created (requires maintainer authorization for fork PRs)
3. 👀 Code review — a maintainer will review your changes
4. 🚀 Merge — once approved, your PR will be merged!

Quick checklist

• PR title follows Conventional Commits (e.g. feat: add dark mode)
• Linked the issue this PR closes (e.g. Closes #123)
• Tested the changes locally (bun run dev)
• Build passes (bun run build)

Useful links

• 📖 CONTRIBUTING.md
• 🐛 Open Issues
• ⭐ Star the repo to support the project!

Happy coding! 🎉

[github-actions]

✅ PR Format Check Passed — @sb123sb123

Basic format checks passed. A maintainer will review your code changes.

This does not mean the PR is approved — it just means the format is correct.