fix(user): 解决缓存时间计算问题

- 修复了剩余秒数计算逻辑，添加随机值避免缓存雪崩
- 防止大量请求同时失效导致系统压力过大

app/controller/api/user/User.php

@@ -3350,7 +3350,7 @@ class User extends BaseController
 
         $now = time();
         $todayEnd = strtotime('today 23:59:59');
-        $remainingSeconds = $todayEnd - $now;
+        $remainingSeconds = $todayEnd - $now + rand(1, 100);
         Cache::set($key, 1, $remainingSeconds);
 
         return app('json')->success($data);