Fix: Blade compilation error in notification template form

The template variable display used nested {{ '{{' }} syntax which
confused Blade's compiler, causing an "Unclosed '(' does not match '}'"
error. Use string concatenation with {!! !!} to output literal braces.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

resources/views/livewire/notifications/notification-template-form.blade.php

@@ -63,7 +63,7 @@ class="w-full px-4 py-2.5 border border-gray-300 rounded-lg focus:ring-2 focus:r
                     <p class="text-xs font-medium text-blue-700 mb-1">{{ __('المتغيرات المتاحة لهذا الحدث:') }}</p>
                     <div class="flex flex-wrap gap-2">
                         @foreach($this->availableVariables as $var)
-                        <code class="px-2 py-0.5 bg-blue-100 text-blue-800 rounded text-xs" dir="ltr">{{ '{{' . $var . '}}' }}</code>
+                        <code class="px-2 py-0.5 bg-blue-100 text-blue-800 rounded text-xs" dir="ltr">{!! '{' . '{' . e($var) . '}' . '}' !!}</code>
                         @endforeach
                     </div>
                 </div>