Add PWA support with install banner and app icons

- Configure @vite-pwa/nuxt module with manifest and service worker
- Add PWA install banner component to login page
- Include app icons (192x192, 512x512) and favicon assets
- Update admin dashboard layout and remove backup section
- Add PWA-related API endpoints and utility scripts

components/PWAInstallBanner.vue

@@ -0,0 +1,239 @@
+<template>
+  <v-card
+    v-if="showBanner"
+    class="pwa-install-banner"
+    elevation="8"
+    color="primary"
+    variant="elevated"
+  >
+    <v-card-text class="pa-4">
+      <v-row align="center" no-gutters>
+        <v-col cols="auto" class="mr-3">
+          <v-avatar size="48" color="white">
+            <v-img src="/icon-192x192.png" alt="MonacoUSA Portal" />
+          </v-avatar>
+        </v-col>
+        
+        <v-col>
+          <div class="text-white">
+            <div class="text-subtitle-1 font-weight-bold mb-1">
+              Install MonacoUSA Portal
+            </div>
+            <div class="text-body-2 text-grey-lighten-2">
+              {{ installMessage }}
+            </div>
+          </div>
+        </v-col>
+        
+        <v-col cols="auto">
+          <v-btn
+            v-if="canInstall"
+            @click="installPWA"
+            color="white"
+            variant="elevated"
+            size="small"
+            class="mr-2"
+            :loading="installing"
+          >
+            <v-icon start>mdi-download</v-icon>
+            Install
+          </v-btn>
+          
+          <v-btn
+            @click="dismissBanner"
+            color="white"
+            variant="text"
+            size="small"
+            icon
+          >
+            <v-icon>mdi-close</v-icon>
+          </v-btn>
+        </v-col>
+      </v-row>
+    </v-card-text>
+  </v-card>
+</template>
+
+<script setup lang="ts">
+interface BeforeInstallPromptEvent extends Event {
+  prompt(): Promise<void>;
+  userChoice: Promise<{ outcome: 'accepted' | 'dismissed' }>;
+}
+
+// Reactive state
+const showBanner = ref(false);
+const canInstall = ref(false);
+const installing = ref(false);
+const installMessage = ref('Add to your home screen for quick access');
+let deferredPrompt: BeforeInstallPromptEvent | null = null;
+
+// Device detection
+const isIOS = computed(() => {
+  if (process.client) {
+    return /iPad|iPhone|iPod/.test(navigator.userAgent);
+  }
+  return false;
+});
+
+const isAndroid = computed(() => {
+  if (process.client) {
+    return /Android/.test(navigator.userAgent);
+  }
+  return false;
+});
+
+const isStandalone = computed(() => {
+  if (process.client) {
+    return window.matchMedia('(display-mode: standalone)').matches ||
+           (window.navigator as any).standalone === true;
+  }
+  return false;
+});
+
+// Install messages based on platform
+const getInstallMessage = () => {
+  if (isIOS.value) {
+    return 'Tap Share → Add to Home Screen to install';
+  } else if (isAndroid.value) {
+    return 'Add to your home screen for quick access';
+  } else {
+    return 'Install this app for a better experience';
+  }
+};
+
+// PWA installation logic
+const installPWA = async () => {
+  if (!deferredPrompt) return;
+  
+  installing.value = true;
+  
+  try {
+    // Show the install prompt
+    await deferredPrompt.prompt();
+    
+    // Wait for the user to respond to the prompt
+    const { outcome } = await deferredPrompt.userChoice;
+    
+    console.log(`PWA install prompt outcome: ${outcome}`);
+    
+    if (outcome === 'accepted') {
+      console.log('✅ PWA installation accepted');
+      showBanner.value = false;
+      localStorage.setItem('pwa-install-dismissed', 'true');
+    }
+    
+    // Clear the deferredPrompt
+    deferredPrompt = null;
+    canInstall.value = false;
+    
+  } catch (error) {
+    console.error('❌ PWA installation error:', error);
+  } finally {
+    installing.value = false;
+  }
+};
+
+const dismissBanner = () => {
+  showBanner.value = false;
+  localStorage.setItem('pwa-install-dismissed', 'true');
+  localStorage.setItem('pwa-install-dismissed-date', new Date().toISOString());
+};
+
+const shouldShowBanner = () => {
+  // Don't show if already dismissed recently (within 7 days)
+  const dismissedDate = localStorage.getItem('pwa-install-dismissed-date');
+  if (dismissedDate) {
+    const daysSinceDismissed = (Date.now() - new Date(dismissedDate).getTime()) / (1000 * 60 * 60 * 24);
+    if (daysSinceDismissed < 7) {
+      return false;
+    }
+  }
+  
+  // Don't show if permanently dismissed
+  if (localStorage.getItem('pwa-install-dismissed') === 'true' && !dismissedDate) {
+    return false;
+  }
+  
+  // Don't show if already installed
+  if (isStandalone.value) {
+    return false;
+  }
+  
+  return true;
+};
+
+// Setup event listeners
+onMounted(() => {
+  if (!process.client) return;
+  
+  installMessage.value = getInstallMessage();
+  
+  // Listen for the beforeinstallprompt event
+  window.addEventListener('beforeinstallprompt', (e: Event) => {
+    console.log('🔔 PWA install prompt available');
+    
+    // Prevent the mini-infobar from appearing on mobile
+    e.preventDefault();
+    
+    // Save the event so it can be triggered later
+    deferredPrompt = e as BeforeInstallPromptEvent;
+    canInstall.value = true;
+    
+    // Show banner if conditions are met
+    if (shouldShowBanner()) {
+      showBanner.value = true;
+    }
+  });
+  
+  // Listen for successful installation
+  window.addEventListener('appinstalled', () => {
+    console.log('✅ PWA was installed successfully');
+    showBanner.value = false;
+    deferredPrompt = null;
+    canInstall.value = false;
+  });
+  
+  // For iOS devices, show banner if not installed and not dismissed
+  if (isIOS.value && shouldShowBanner()) {
+    showBanner.value = true;
+  }
+});
+</script>
+
+<style scoped>
+.pwa-install-banner {
+  position: fixed;
+  bottom: 20px;
+  left: 20px;
+  right: 20px;
+  z-index: 1000;
+  max-width: 400px;
+  margin: 0 auto;
+  border-radius: 12px !important;
+  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3) !important;
+}
+
+@media (max-width: 600px) {
+  .pwa-install-banner {
+    left: 16px;
+    right: 16px;
+    bottom: 16px;
+  }
+}
+
+/* Animation */
+.pwa-install-banner {
+  animation: slideUp 0.3s ease-out;
+}
+
+@keyframes slideUp {
+  from {
+    transform: translateY(100px);
+    opacity: 0;
+  }
+  to {
+    transform: translateY(0);
+    opacity: 1;
+  }
+}
+</style>