Improve text visibility in atom and dusk themes

- Add CSS variable support to dusk theme components for dynamic text colors
- Fix low-contrast preset color combinations (cyberpunk, neon, magma, forest, obsidian, space)
- Add text-shadow utility classes and apply to site header and backgrounds
- Style logout buttons as proper buttons matching other button styles
- Fix hardcoded text colors in atom theme components

resources/themes/dusk/views/components/page-header.blade.php

@@ -6,12 +6,12 @@
     @endif
 
    <div class="flex-col px-2">
-       <div class="text-lg font-bold text-gray-100 flex items-center">
+       <div class="text-lg font-bold flex items-center" style="color: var(--color-text);">
            {{ $slot }}
        </div>
 
        @if(isset($subHeader))
-           <p class="text-gray-500">{{ $subHeader }}</p>
+           <p class="text-muted">{{ $subHeader }}</p>
        @endif
    </div>
 </div>