fix: 修复统计近7天token消耗时角色过滤条件错误

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

@@ -44,6 +44,7 @@ public class UsageStatisticsService : ApplicationService, IUsageStatisticsServic
         // 从Message表统计近7天的token消耗
         var dailyUsage = await _messageRepository._DbQueryable
             .Where(x => x.UserId == userId)
+            .Where(x => x.Role == "assistant" || x.Role == "system")
             .Where(x => x.CreationTime >= startDate && x.CreationTime < endDate.AddDays(1))
             .GroupBy(x => x.CreationTime.Date)
             .Select(g => new