feat(fullstack): Add server health check with overlay

legalconsenthub/components/ServerConnectionOverlay.vue

@@ -0,0 +1,55 @@
+<template>
+  <Teleport to="body">
+    <div
+      v-if="!isServerAvailable"
+      class="fixed inset-0 z-50 bg-black/50 backdrop-blur-sm flex items-center justify-center"
+      @click.prevent
+      @keydown.prevent
+    >
+      <div class="bg-white dark:bg-gray-900 rounded-lg shadow-xl p-8 max-w-md mx-4 text-center">
+        <!-- Loading Spinner -->
+        <div class="mb-6 flex justify-center">
+          <UIcon name="i-heroicons-arrow-path" class="w-12 h-12 text-primary-500 animate-spin" />
+        </div>
+
+        <!-- Title -->
+        <h2 class="text-xl font-semibold text-gray-900 dark:text-white mb-4">
+          {{ t('serverConnection.title') }}
+        </h2>
+
+        <!-- Description -->
+        <p class="text-gray-600 dark:text-gray-400 mb-6 leading-relaxed">
+          {{ t('serverConnection.message') }}
+        </p>
+
+        <!-- Status Information -->
+        <div class="space-y-2 text-sm text-gray-500 dark:text-gray-400">
+          <div v-if="isChecking" class="flex items-center justify-center gap-2">
+            <UIcon name="i-heroicons-arrow-path" class="w-4 h-4 animate-spin" />
+            <span>{{ t('serverConnection.checking') }}</span>
+          </div>
+
+          <div v-if="lastCheckTime" class="text-xs">
+            {{ t('serverConnection.lastCheck') }}:
+            {{ new Date(lastCheckTime).toLocaleTimeString() }}
+          </div>
+
+          <div class="text-xs">
+            {{ t('serverConnection.retryInfo') }}
+          </div>
+        </div>
+
+        <!-- Optional: Manual retry button -->
+        <UButton v-if="!isChecking" variant="ghost" size="sm" class="mt-4" @click="void checkServerHealth()">
+          <UIcon name="i-heroicons-arrow-path" class="w-4 h-4 mr-1" />
+          {{ t('serverConnection.retryNow') }}
+        </UButton>
+      </div>
+    </div>
+  </Teleport>
+</template>
+
+<script setup lang="ts">
+const { t } = useI18n()
+const { isServerAvailable, isChecking, lastCheckTime, checkServerHealth } = useServerHealth()
+</script>