Add Google Analytics tracking to all pages

[Copilot]

Adds Google Analytics (G-HL8F2RJW68) to all HTML pages by inserting the gtag.js snippet into both template sources.

Changes

• templates/index.html: Added GA snippet before closing </head> tag
• templates/slug-template.html: Added GA snippet before closing </head> tag

The generator produces 91 HTML files from these templates. Generated files are excluded via .gitignore and will be rebuilt on deployment.

<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-HL8F2RJW68"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-HL8F2RJW68');
</script>

Screenshot

Homepage with analytics enabled:

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Add Google Analytics</issue_title>
<issue_description>Here is the code block for Google Analytics on all HTML pages:

<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-HL8F2RJW68"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'G-HL8F2RJW68');
</script>
```</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

• Fixes Add Google Analytics #24

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