feat: 转存记录记录文件大小, 详情展示使用账号+文件大小+时间格式

- quark/baidu 驱动 saveFromShare 返回 fileSize 总大小
- cloud.service.ts 写入 file_size 字段（非null时转字符串）
- 详情页新增文件大小展示（formatFileSize 自动格式化）
- 详情页时间改为 formatTime(yyyy-MM-dd HH:mm:ss)
- SaveRecords 时间格式: 05-15 → 2026-05-15

packages/backend/src/cloud/drivers/quark-storage.ts

@@ -28,6 +28,7 @@ export async function saveFromShare(
   renamed?: string[];
   fileCount?: number;
   folderCount?: number;
+  fileSize?: number;
   originalFolderName?: string;
 }> {
   try {
@@ -203,6 +204,10 @@ export async function saveFromShare(
       }
     }
 
+    // Calculate total file size
+    const allFiles = topDir && childFiles ? childFiles : topFiles;
+    const fileSize = allFiles.reduce((sum, f) => sum + (Number(f.size) || 0), 0);
+
     const renameMsg = renamed.length > 0
       ? `，已重命名 ${renamed.length} 个文件`
       : '';
@@ -218,6 +223,7 @@ export async function saveFromShare(
       renamed: renamed.map(r => `${r.original} → ${r.renamed}`),
       fileCount,
       folderCount,
+      fileSize,
       originalFolderName,
     };
   } catch (err: any) {