Deck list work

SVSim.EmulatedEntrypoint/Models/Dtos/CompetitionInfo.cs

@@ -0,0 +1,23 @@
+using MessagePack;
+using System.Text.Json.Serialization;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos;
+
+/// <summary>
+/// Tournament-window block returned by /mypage/index. Client constructs
+/// ArenaCompetition(base.ResponseData) at MyPageTask.cs:110, which then reads
+/// `responseData["data"]["competition_info"]["is_competition_period"]`
+/// unconditionally (ArenaCompetition.cs:232-233). The remaining fields
+/// (deck_format, entry_start_time, freebie_status, featured_entry_reward_list,
+/// etc.) are only read when IsCompetitionPeriod is true, so the minimum-viable
+/// payload while we have no tournament implementation is just the bool=false.
+/// Prod emits the same `{"is_competition_period":false}` shape when no
+/// tournament is active.
+/// </summary>
+[MessagePackObject]
+public class CompetitionInfo
+{
+    [JsonPropertyName("is_competition_period")]
+    [Key("is_competition_period")]
+    public bool IsCompetitionPeriod { get; set; }
+}