feat(admin): add announcement preview action

frontend/src/views/admin/AnnouncementsView.vue

@@ -114,12 +114,19 @@
 
           <template #cell-actions="{ row }">
             <div class="flex items-center space-x-1">
+              <button
+                @click="openPreview(row)"
+                class="flex flex-col items-center gap-0.5 rounded-lg p-1.5 text-gray-500 transition-colors hover:bg-blue-50 hover:text-blue-600 dark:hover:bg-blue-900/20 dark:hover:text-blue-400"
+                :title="t('admin.announcements.preview')"
+              >
+                <Icon name="eye" size="sm" />
+              </button>
               <button
                 @click="openReadStatus(row)"
                 class="flex flex-col items-center gap-0.5 rounded-lg p-1.5 text-gray-500 transition-colors hover:bg-blue-50 hover:text-blue-600 dark:hover:bg-blue-900/20 dark:hover:text-blue-400"
                 :title="t('admin.announcements.readStatus')"
               >
-                <Icon name="eye" size="sm" />
+                <Icon name="chartBar" size="sm" />
               </button>
               <button
                 @click="openEditDialog(row)"
@@ -240,6 +247,12 @@
       :announcement-id="readStatusAnnouncementId"
       @close="showReadStatusDialog = false"
     />
+
+    <AnnouncementPopup
+      :announcement="previewAnnouncement"
+      preview
+      @close="previewAnnouncement = null"
+    />
   </AppLayout>
 </template>
 
@@ -265,6 +278,7 @@ import Icon from '@/components/icons/Icon.vue'
 
 import AnnouncementTargetingEditor from '@/components/admin/announcements/AnnouncementTargetingEditor.vue'
 import AnnouncementReadStatusDialog from '@/components/admin/announcements/AnnouncementReadStatusDialog.vue'
+import AnnouncementPopup from '@/components/common/AnnouncementPopup.vue'
 
 const { t } = useI18n()
 const appStore = useAppStore()
@@ -588,6 +602,11 @@ async function confirmDelete() {
 // ===== Read status =====
 const showReadStatusDialog = ref(false)
 const readStatusAnnouncementId = ref<number | null>(null)
+const previewAnnouncement = ref<Announcement | null>(null)
+
+function openPreview(row: Announcement) {
+  previewAnnouncement.value = row
+}
 
 function openReadStatus(row: Announcement) {
   readStatusAnnouncementId.value = row.id