feat: 文档预览器i18n适配

app/components/shared/FilePreviewer.vue

@@ -21,7 +21,7 @@
           :disabled="!fileMeta"
           @click="openInNewTab"
         >
-          在新标签打开
+          {{ $t('document-action.open-in-new-tab') }}
         </button>
         <button
           class="px-3 py-1.5 rounded bg-blue-600 text-white hover:bg-blue-700 disabled:opacity-50"
@@ -29,7 +29,7 @@
           :disabled="!fileMeta"
           @click="download"
         >
-          下载
+          {{ $t('document-action.download') }}
         </button>
       </div>
     </header>
@@ -37,7 +37,7 @@
     <div class="flex-1 overflow-hidden">
       <!-- 加载状态 -->
       <div v-if="pending" class="h-48 grid place-items-center border rounded">
-        正在加载...
+        {{ $t('loading') }}
       </div>
       <div
         v-else-if="errorText"