style(ui): enlarge mobile theme toggle touch target and optimize script directives

[eaitbrahim]

Problem

1. The theme toggle button (.theme-toggle) is currently 33.6px (2.1rem), which is below the recommended 40-44px touch target size for mobile devices.
2. French navigation labels near 1024px screen width crowd before the mobile hamburger menu triggers.
3. BaseHead.astro triggers Astro static analyzer hints for script tags with attributes missing explicit is:inline.

Proposed Fixes

• Increase .theme-toggle button size to 40px (2.5rem) in global.css for mobile touch ergonomics.
• Refine French navigation spacing on intermediate viewports.
• Explicitly add is:inline directives to script tags in BaseHead.astro.