🗑️ Remove some unused code

DysonNetwork.Sphere/Chat/ChatService.cs

@@ -623,7 +623,6 @@ public partial class ChatService(
             message.Attachments = queryResult.Files.Select(CloudFileReferenceObject.FromProtoValue).ToList();
         }
 
-        message.EditedAt = SystemClock.Instance.GetCurrentInstant();
         db.Update(message);
         await db.SaveChangesAsync();
 

DysonNetwork.Sphere/Chat/Message.cs

@@ -50,15 +50,4 @@ public class MessageReaction : ModelBase
 
     [MaxLength(256)] public string Symbol { get; set; } = null!;
     public MessageReactionAttitude Attitude { get; set; }
-}
-
-/// <summary>
-/// The data model for updating the last read at field for chat member,
-/// after the refactor of the unread system, this no longer stored in the database.
-/// Not only used for the data transmission object
-/// </summary>
-[NotMapped]
-public class MessageReadReceipt
-{
-    public Guid SenderId { get; set; }
 }