Update: Mutli Channel Support

RelayClient/Models/SocketEncryptedMessage.cs

@@ -5,6 +5,7 @@ public class SocketEncryptedMessage
     public required string Type { get; set; }
     public required string SenderUsername { get; set; }
     public string? RecipientUsername { get; set; }
+    public required string ChannelId { get; set; }
     public required string CipherText { get; set; }
     public required string Nonce { get; set; }
     public required string Tag { get; set; }