Add placeholder images, enhance alert styles, and implement theme toggle component with dark mode support

resources/views/livewire/theme-toggle-component.blade.php

@@ -0,0 +1,28 @@
+<label for="theme-toggle" class="cursor-pointer">
+    <input 
+        type="checkbox" 
+        id="theme-toggle" 
+        class="hidden" 
+        wire:model.live="isDark"
+        wire:change="toggleTheme"
+    >
+    <div
+        class="inline-flex items-center justify-center p-2 text-gray-500 transition-colors hover:text-primary dark:text-gray-400 dark:hover:text-primary theme-toggle-btn"
+        role="button"
+        aria-label="Toggle dark mode"
+    >
+        <i class="text-xl fas {{ $isDark ? 'fa-sun' : 'fa-moon' }}"></i>
+    </div>
+</label>
+
+<script>
+    document.addEventListener('livewire:init', () => {
+        Livewire.on('theme-changed', ({ theme }) => {
+            if (theme === 'dark') {
+                document.documentElement.classList.add('dark');
+            } else {
+                document.documentElement.classList.remove('dark');
+            }
+        });
+    });
+</script>