docs: implement native-style version badge in header

[PythonWoods-Dev]

Summary

This PR refines the documentation header by integrating the project version as a native-style "fact" within the repository widget.

Key Changes

• Header Structure: Wrapped partials/source.html and the version string in a .zz-source-wrapper to maintain layout consistency.
• Visual Alignment: Applied a 2.1rem left padding to the version tag to align it perfectly under the repository name, mimicking the native Material for MkDocs "stars/forks" look.
• Styling: Used tag-outline.svg with opacity: 0.7 and currentColor fill to ensure a seamless fit in both light and dark modes.
• Responsiveness: Added a media query to hide the version badge on small screens (< 480px) to prevent header overcrowding.

Context

Previously, the version was displayed as a separate box which broke the header's design language. This update ensures Zenzic's documentation follows the ecosystem's best practices for UI/UX.