Things were working, suddenly regressed

SVSim.EmulatedEntrypoint/Models/Dtos/GuildNotification.cs

@@ -0,0 +1,31 @@
+using MessagePack;
+using System.Text.Json.Serialization;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos;
+
+/// <summary>
+/// guild_notification on /mypage/index. Consumed by
+/// MyPageNotifications.GuildNotification.SetGuildNotification. Prod sends nulls
+/// for guild_id / guild_room_message_id when the viewer isn't in a guild; with
+/// WhenWritingNull those keys are omitted on our wire, which is equivalent
+/// since the parser is null-tolerant.
+/// </summary>
+[MessagePackObject]
+public class GuildNotification
+{
+    [JsonPropertyName("guild_id")]
+    [Key("guild_id")]
+    public long? GuildId { get; set; }
+
+    [JsonPropertyName("guild_room_message_id")]
+    [Key("guild_room_message_id")]
+    public long? GuildRoomMessageId { get; set; }
+
+    [JsonPropertyName("is_join_request")]
+    [Key("is_join_request")]
+    public bool IsJoinRequest { get; set; }
+
+    [JsonPropertyName("is_invited")]
+    [Key("is_invited")]
+    public bool IsInvited { get; set; }
+}