refactor: Rename fonts to Fonts (PascalCase consistency)

- Rename Assets/fonts/ to Assets/Fonts/
- Update all references in PHP and CSS files
- Consistent with Css, Js, Vendor naming

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Co-Authored-By: Claude <noreply@anthropic.com>

functions-addon.php

@@ -48,7 +48,7 @@ add_action('wp_head', function() {
 
     foreach ($critical_fonts as $font) {
         printf(
-            '<link rel="preload" href="%s/Assets/fonts/%s" as="font" type="font/woff2" crossorigin>%s',
+            '<link rel="preload" href="%s/Assets/Fonts/%s" as="font" type="font/woff2" crossorigin>%s',
             esc_url($theme_url),
             esc_attr($font),
             "\n"