fix: replace dead Universal Analytics snippet with GA4 in all 11 language subpages

[ARYANPATEL-BIT]

Summary

Fixes the dead Universal Analytics tracking reported in #<ISSUE_NUMBER> across all 11 language-specific subpages.

Problem

All 11 language subpages were still running the old analytics.js Universal Analytics snippet with a UA-56251309-2 tracking ID. Google sunset UA on July 1, 2023, so these pages have been recording zero analytics data since then.

Changes

Removed the old UA snippet from all 11 language files

Replaced with the modern GA4 snippet matching app/index.html:

<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-WV41BWS391"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-WV41BWS391');
</script>

Type of Change

• Bug fix

Testing

• Opened each language subpage in browser
• Verified in browser DevTools Network tab that analytics.js is no longer loaded
• Verified gtag.js is loaded correctly
• Confirmed events appearing in GA4 dashboard DebugView

Related Issue

Closes #127

[robertodauria]

Thanks for the contribution. Closing this as #83 already addresses it. We aim to merge #83 next week, which will give contributors a stable, modern base to work from. We'd encourage you to review it and open any future PRs on top of that.