feat: 生成的唯一消息id 优化

utils/index.js

@@ -13,7 +13,12 @@ export class IdUtils {
    * @returns {string} 消息ID
    */
   static generateMessageId() {
-    return "mid" + new Date().getTime();
+    const timestamp = new Date().getTime();
+    const chars = "abcdefghijklmnopqrstuvwxyz";
+    const randomStr = Array.from({ length: 4 }, () =>
+      chars.charAt(Math.floor(Math.random() * chars.length))
+    ).join("");
+    return "mid"+ randomStr + timestamp;
   }
 }