feat: 添加深色模式和照片预览优化

- 新增全局深色模式切换功能，支持手动切换和跟随系统主题
- 优化照片墙预览，使用ElImageViewer组件支持左右切换
- 引入Element Plus深色模式相关样式文件

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/views/api/PhotoWall.vue

@@ -75,10 +75,16 @@
       @current-change="pageChange">
     </el-pagination>
   </div>
+  <el-image-viewer
+    v-if="previewVisible"
+    :url-list="previewUrlList"
+    :initial-index="previewIndex"
+    @close="previewVisible = false"
+  />
 </div>
 </template>
 <script setup lang="ts">
-import { ref, h } from 'vue'
+import { ref } from 'vue'
 import { useStore } from 'vuex'
 import { ElMessage, ElMessageBox } from 'element-plus'
 import { MsgResult, Page } from '@/model/common.dto'
@@ -106,8 +112,11 @@ const store = useStore()
 const { loading, total, search, setLoadData, loadDataBase, reset, pageChange, pageSizeChange } = useBaseList(new PhotoWallPage())
 
 const allowUploadExt = ['jpg', 'jpeg', 'png']
-const photowallData = ref([])
+const photowallData = ref<PhotoWallModel[]>([])
 const isUploading = ref(false)
+const previewVisible = ref(false)
+const previewUrlList = ref<string[]>([])
+const previewIndex = ref(0)
 
 let selectedData: string[] = []
 
@@ -157,15 +166,11 @@ function uploadError(error: Error) {
   ElMessage.error(error.message)
 }
 async function preview(row: PhotoWallModel) {
-  const previewHeight = Math.floor(row.height * (500 / row.width))
   const pictureCdn = await http.get('/api/v2/common/config/picture_cdn')
-  ElMessageBox({
-    title: '图片预览',
-    message: h('img', { style: `width:500px;height:${previewHeight}px;`, src: `${pictureCdn}/${row.name}` }, ''),
-    showCancelButton: false,
-    confirmButtonText: '关闭',
-    customStyle: {width: '530px', maxWidth: 'unset'}
-  }).catch(() => {})
+  const index = photowallData.value.findIndex(item => item._id === row._id)
+  previewUrlList.value = photowallData.value.map(item => `${pictureCdn}/${item.name}`)
+  previewIndex.value = index >= 0 ? index : 0
+  previewVisible.value = true
 }
 
 // created