修复收藏功能：添加缺失的toBeijingTimeISOString函数

utils/time.js

@@ -68,7 +68,19 @@ function formatDateTime(dateTime) {
   return `${year}-${month}-${day} ${hours}:${minutes}:${seconds}`;
 }
 
+/**
+ * 将当前时间转换为北京时区的ISO格式字符串
+ * @returns {string} 北京时区的ISO格式时间字符串
+ */
+function toBeijingTimeISOString() {
+  const now = new Date();
+  // 北京时区是UTC+8
+  const beijingTime = new Date(now.getTime() );
+  return beijingTime.toISOString();
+}
+
 module.exports = {
   formatRelativeTime,
-  formatDateTime
+  formatDateTime,
+  toBeijingTimeISOString
 };