feat: Add AppHeader component and implement the default application layout.

Frontend-Learner/components/common/AppHeader.vue

@@ -10,10 +10,7 @@ defineProps<{
   showSearch?: boolean
 }>()
 
-const emit = defineEmits<{
-  /** Emitted when the hamburger menu is clicked */
-  toggleSidebar: []
-}>()
+
 
 const searchText = ref('')
 </script>
@@ -21,15 +18,7 @@ const searchText = ref('')
 <template>
   <q-toolbar class="bg-transparent text-slate-800 dark:text-white h-16 px-4">
     <!-- Mobile Menu Toggle -->
-    <q-btn
-      flat
-      round
-      dense
-      icon="menu"
-      @click="emit('toggleSidebar')"
-      class="md:hidden mr-2 text-slate-700 dark:text-white"
-      aria-label="Menu"
-    />
+
 
     <!-- Branding -->
     <div class="flex items-center gap-2 cursor-pointer" @click="navigateTo('/dashboard')">