feat(KAN-17): add Emerald design system and resilient themes

app/Http/Middleware/HandleAppearance.php

@@ -16,7 +16,11 @@ class HandleAppearance
      */
     public function handle(Request $request, Closure $next): Response
     {
-        View::share('appearance', $request->cookie('appearance') ?? 'system');
+        $appearance = $request->cookie('appearance');
+        $appearance = in_array($appearance, ['light', 'dark', 'system'], true) ? $appearance : 'system';
+
+        $request->attributes->set('appearance', $appearance);
+        View::share('appearance', $appearance);
 
         return $next($request);
     }

app/Http/Middleware/HandleInertiaRequests.php

@@ -46,6 +46,7 @@ class HandleInertiaRequests extends Middleware
         return [
             ...parent::share($request),
             'name' => config('app.name'),
+            'appearance' => $request->attributes->get('appearance', 'system'),
             'localization' => [
                 'locale' => app()->getLocale(),
                 'timeZone' => config('app.timezone'),