前端：

1、优化消息排序逻辑
2、新增加载历史消息
3、修复已知问题
后端：
1、优化消息排序逻辑
2、增加用户信息缓存机制
3、修改日期类型为DateTimeOffset改善时区信息丢失问题
3、修复了已知问题
数据库：
1、新增SequenceId字段用于消息排序
2、新增ClientMsgId字段用于客户端消息回执

backend/IM_API/Domain/Events/DomainEvent.cs

@@ -5,7 +5,7 @@ namespace IM_API.Domain.Events
     public abstract record DomainEvent: IEvent
     {
         public Guid EventId { get; init; } = Guid.NewGuid();
-        public DateTime OccurredAt { get; init; } = DateTime.UtcNow;
+        public DateTimeOffset OccurredAt { get; init; } = DateTime.Now;
         public long OperatorId { get; init; }
         public string AggregateId { get; init; } = "";
         public abstract string EventType { get; }

backend/IM_API/Domain/Events/FriendAddEvent.cs

@@ -19,7 +19,7 @@ namespace IM_API.Domain.Events
         /// <summary>
         /// 好友关系创建时间
         /// </summary>
-        public DateTime Created { get; init; }
+        public DateTimeOffset Created { get; init; }
 
     }
 }

backend/IM_API/Domain/Events/MessageCreatedEvent.cs

@@ -8,13 +8,14 @@ namespace IM_API.Domain.Events
         public override string EventType => "IM.MESSAGE.MESSAGE_CREATED";
         public ChatType ChatType { get; set; }
         public MessageMsgType MessageMsgType { get; set; }
-        public int MessageId { get; set; }
+        public long SequenceId { get; set; }
         public string MessageContent { get; set; }
         public int MsgSenderId { get; set; }
         public int MsgRecipientId { get; set; }
         public MessageState State { get; set; }
-        public DateTime MessageCreated { get; set; }
+        public DateTimeOffset MessageCreated { get; set; }
         public string StreamKey { get; set; }
+        public Guid ClientMsgId { get; set; }