fix: 为领奖与兑换流程添加分布式锁，防止并发重复操作

- 在 DailyTaskService 与 ActivationCodeService 中引入 Medallion.Threading。
- 通过 LazyServiceProvider 获取 IDistributedLockProvider（DistributedLock 属性）。
- 在 ClaimTaskRewardAsync（DailyTaskService）和 RedeemAsync（ActivationCodeService）中使用 AcquireLockAsync 加锁（基于 userId / activation code），用于自旋等待、防抖，避免并发导致的重复发放或重复兑换问题。

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Application/Services/Activities/DailyTaskService.cs

@@ -1,3 +1,4 @@
+using Medallion.Threading;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.Extensions.Logging;
 using SqlSugar;
@@ -23,7 +24,7 @@ public class DailyTaskService : ApplicationService
     private readonly ISqlSugarRepository<MessageAggregateRoot> _messageRepository;
     private readonly ISqlSugarRepository<PremiumPackageAggregateRoot> _premiumPackageRepository;
     private readonly ILogger<DailyTaskService> _logger;
-
+    private IDistributedLockProvider DistributedLock => LazyServiceProvider.LazyGetRequiredService<IDistributedLockProvider>();
     // 任务配置
     private readonly Dictionary<int, (long RequiredTokens, long RewardTokens, string Name, string Description)>
         _taskConfigs = new()
@@ -113,6 +114,11 @@ public class DailyTaskService : ApplicationService
     public async Task ClaimTaskRewardAsync(ClaimTaskRewardInput input)
     {
         var userId = CurrentUser.GetId();
+        //自旋等待，防抖
+        await using var handle =
+            await DistributedLock.AcquireLockAsync($"Yi:AiHub:ClaimTaskRewardLock:{userId}");
+        
+        
         var today = DateTime.Today;
 
         // 1. 验证任务等级