fix: worksheet 展示时间修改

miniprogram/pages/category/category.ts

@@ -82,6 +82,13 @@ function debugLogWorksheetStatsAfterCategoryLoad(
 
 // --- 调试块结束 ---
 
+function toContentDate(raw: Record<string, any>): string {
+    const ts = raw.contentUpdatedAt || raw.createdAt;
+    return ts
+        ? new Date(ts).toISOString().slice(0, 10)
+        : new Date().toISOString().slice(0, 10);
+}
+
 /** 将云端 worksheet 原始数据转换为 CategoryItem */
 function toDisplayItem(raw: Record<string, any>): CategoryItem {
     const difficulty = (Number(raw.difficulty) || 2) as 1 | 2 | 3 | 4;
@@ -101,9 +108,7 @@ function toDisplayItem(raw: Record<string, any>): CategoryItem {
         available: true,
         likes: Number(raw.likes) || 0,
         downloads: Number(raw.downloads) || 0,
-        date: raw.updatedAt
-            ? new Date(raw.updatedAt).toISOString().slice(0, 10)
-            : new Date().toISOString().slice(0, 10),
+        date: toContentDate(raw),
         updatedAt: raw.updatedAt ? String(raw.updatedAt) : '',
     };
 }