feat(arena-colosseum): lobby + constructed entry (phase 1)

Closes 5 of arena-colosseum's 16 spec shapes (1/16 → 6/16). Lobby reads
(/top, /get_fee_info, /event_info) render an empty "no event scheduled"
payload by default; /entry + /register_deck activate via admin-flipped
ColosseumSeason + ColosseumRounds config sections.

* Schema: ViewerArenaColosseumRun standalone table (unique on ViewerId)
  with jsonb run-state columns mirroring ViewerArenaTwoPickRun.
* Config sections: ColosseumSeasonConfig (event-level), ColosseumRoundsConfig
  (the 3-round bracket). Empty defaults — IsColosseumPeriod=false.
* Migration AddArenaColosseumRun (DDL only; seed rows come from the section
  ShippedDefaults via EnsureSeedDataAsync).
* DTOs: ColosseumLobbyInfo (round-level, /top + /get_fee_info), ColosseumEventInfo
  (event-level, /event_info), ColosseumOwnStatus (shared status block),
  ColosseumEntryRef, ColosseumFeeList, ColosseumUserDeck, ColosseumBattleResults,
  ColosseumRoundDetail + ColosseumGroupRow. EventInfoResponse uses explicit
  [JsonPropertyName("1"|"2"|"3")] for the string-keyed rounds shape per spec.
* Controller: ArenaColosseumController replaces the 1-action stub with
  the five lifecycle endpoints. /top emits leader_skin_id even when 0
  (project_wire_null_policy override).
* Tests: 11 controller-level tests + 6 config round-trip tests covering
  empty-season payloads, run-seeded /top round-trip, crystal/rupy entry
  debits, now_round_id mismatch rejection, deck_no_list round-trip + reject.

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/ColosseumBattleResults.cs

@@ -0,0 +1,15 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
+
+[MessagePackObject]
+public class ColosseumBattleResults
+{
+    [JsonPropertyName("win_count")] [Key("win_count")]
+    public int WinCount { get; set; }
+
+    /// <summary>0 = loss, 1 = win. Client iterates as bool list.</summary>
+    [JsonPropertyName("result_list")] [Key("result_list")]
+    public List<int> ResultList { get; set; } = new();
+}

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/ColosseumEntryRef.cs

@@ -0,0 +1,16 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
+
+/// <summary>Wire <c>entry_info</c> object on <c>/top</c> and <c>/entry</c>. Reused across endpoints.</summary>
+[MessagePackObject]
+public class ColosseumEntryRef
+{
+    [JsonPropertyName("id")] [Key("id")]
+    public long Id { get; set; }
+
+    /// <summary>Used by <c>/entry</c> only — Format enum integer. Top emits via colosseum_info.</summary>
+    [JsonPropertyName("deck_format")] [Key("deck_format")]
+    public int? DeckFormat { get; set; }
+}

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/ColosseumEventInfo.cs

@@ -0,0 +1,63 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
+
+/// <summary>
+/// Event-level descriptor used by <c>/event_info</c> only — distinct shape from
+/// <see cref="ColosseumInfo"/>: only <c>format</c>, the event window, the announce id,
+/// and the final-round eliminate count. The client's <c>ColosseumDetailTask</c> reads
+/// these five fields plus the three string-keyed rounds.
+/// </summary>
+[MessagePackObject]
+public class ColosseumEventInfo
+{
+    /// <summary>Event format. Mapped via <c>ApiRuleParseAndSet</c> on the client.</summary>
+    [JsonPropertyName("format")] [Key("format")]
+    public int Format { get; set; }
+
+    [JsonPropertyName("start_time")] [Key("start_time")]
+    public string StartTime { get; set; } = "";
+
+    [JsonPropertyName("end_time")] [Key("end_time")]
+    public string EndTime { get; set; } = "";
+
+    /// <summary>Optional — emit <c>null</c> when no announce content is configured.</summary>
+    [JsonPropertyName("announce_id")] [Key("announce_id")]
+    public string? AnnounceId { get; set; }
+
+    [JsonPropertyName("final_round_eliminate_count")] [Key("final_round_eliminate_count")]
+    public int FinalRoundEliminateCount { get; set; }
+}
+
+[MessagePackObject]
+public class ColosseumRoundDetail
+{
+    [JsonPropertyName("start_time")] [Key("start_time")]
+    public string StartTime { get; set; } = "";
+
+    [JsonPropertyName("end_time")] [Key("end_time")]
+    public string EndTime { get; set; } = "";
+
+    [JsonPropertyName("is_now_round")] [Key("is_now_round")]
+    public bool IsNowRound { get; set; }
+
+    [JsonPropertyName("round_detail")] [Key("round_detail")]
+    public List<ColosseumGroupRow> RoundDetail { get; set; } = new();
+}
+
+[MessagePackObject]
+public class ColosseumGroupRow
+{
+    [JsonPropertyName("group")] [Key("group")]
+    public string Group { get; set; } = "";
+
+    [JsonPropertyName("max_battle_count")] [Key("max_battle_count")]
+    public int MaxBattleCount { get; set; }
+
+    [JsonPropertyName("breakthrough_number")] [Key("breakthrough_number")]
+    public int BreakthroughNumber { get; set; }
+
+    [JsonPropertyName("entry_number")] [Key("entry_number")]
+    public int EntryNumber { get; set; }
+}

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/ColosseumFeeList.cs

@@ -0,0 +1,17 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
+
+[MessagePackObject]
+public class ColosseumFeeList
+{
+    [JsonPropertyName("rupy_cost")] [Key("rupy_cost")]
+    public int RupyCost { get; set; }
+
+    [JsonPropertyName("ticket_cost")] [Key("ticket_cost")]
+    public int TicketCost { get; set; }
+
+    [JsonPropertyName("crystal_cost")] [Key("crystal_cost")]
+    public int CrystalCost { get; set; }
+}

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/ColosseumInfo.cs

@@ -0,0 +1,81 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+using SVSim.EmulatedEntrypoint.Models.Dtos;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
+
+/// <summary>
+/// Round-level Colosseum descriptor. Shared by <c>/top</c> and <c>/get_fee_info</c> via
+/// the client's static <c>ColosseumEntryInfoTask.SetColosseumInfo</c> helper. When
+/// <see cref="IsColosseumPeriod"/> is <c>false</c>, the client skips parsing every other
+/// field — server still emits this minimal payload so the lobby renders cleanly.
+/// <para>
+/// Distinct from <see cref="SVSim.EmulatedEntrypoint.Models.Dtos.ColosseumInfo"/> (the
+/// captured prod <c>/mypage/index</c> shape — stringly-typed and read-only). This is the
+/// per-endpoint Colosseum-family shape. <c>/event_info</c> uses yet a third shape —
+/// <see cref="ColosseumEventInfo"/>.
+/// </para>
+/// </summary>
+[MessagePackObject]
+public class ColosseumLobbyInfo
+{
+    /// <summary>Master gate. <c>false</c> = lobby renders empty.</summary>
+    [JsonPropertyName("is_colosseum_period")] [Key("is_colosseum_period")]
+    public bool IsColosseumPeriod { get; set; }
+
+    /// <summary>Format enum (Rotation=0, Unlimited=1, TwoPick=10, HOF=31, ...).</summary>
+    [JsonPropertyName("deck_format")] [Key("deck_format")]
+    public int? DeckFormat { get; set; }
+
+    /// <summary>STRING wire shape: <c>"0"</c>/<c>"1"</c>. Client parses with
+    /// <c>jsonData.ToString() == "1"</c>.</summary>
+    [JsonPropertyName("is_normal_two_pick")] [Key("is_normal_two_pick")]
+    public string? IsNormalTwoPick { get; set; }
+
+    [JsonPropertyName("colosseum_name")] [Key("colosseum_name")]
+    public string? ColosseumName { get; set; }
+
+    [JsonPropertyName("is_round_period")] [Key("is_round_period")]
+    public bool? IsRoundPeriod { get; set; }
+
+    /// <summary>Wire STRING used by the client as a UI color/theme code.</summary>
+    [JsonPropertyName("is_special_mode")] [Key("is_special_mode")]
+    public string? IsSpecialMode { get; set; }
+
+    [JsonPropertyName("card_pool_name")] [Key("card_pool_name")]
+    public string? CardPoolName { get; set; }
+
+    /// <summary>Present during round period — current stage number (1..3).</summary>
+    [JsonPropertyName("now_round")] [Key("now_round")]
+    public int? NowRound { get; set; }
+
+    /// <summary>Present outside round period — next stage number.</summary>
+    [JsonPropertyName("next_round")] [Key("next_round")]
+    public int? NextRound { get; set; }
+
+    [JsonPropertyName("start_time")] [Key("start_time")]
+    public string? StartTime { get; set; }
+
+    [JsonPropertyName("end_time")] [Key("end_time")]
+    public string? EndTime { get; set; }
+
+    [JsonPropertyName("is_display_tips")] [Key("is_display_tips")]
+    public int? IsDisplayTips { get; set; }
+
+    [JsonPropertyName("colosseum_id")] [Key("colosseum_id")]
+    public int? ColosseumId { get; set; }
+
+    [JsonPropertyName("tips_id")] [Key("tips_id")]
+    public int? TipsId { get; set; }
+
+    [JsonPropertyName("is_all_card_enabled")] [Key("is_all_card_enabled")]
+    public int? IsAllCardEnabled { get; set; }
+
+    /// <summary>Reuses the captured <c>/mypage/index</c> shape — single
+    /// <c>sales_period_time</c> field per prod capture.</summary>
+    [JsonPropertyName("sales_period_info")] [Key("sales_period_info")]
+    public ColosseumSalesPeriodInfo? SalesPeriodInfo { get; set; }
+
+    [JsonPropertyName("strategy_pick_num")] [Key("strategy_pick_num")]
+    public int? StrategyPickNum { get; set; }
+}

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/ColosseumOwnStatus.cs

@@ -0,0 +1,33 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
+
+/// <summary>
+/// Per-viewer Colosseum state. All fields optional — when the viewer has no run, ALL fields
+/// are null and the global <c>WhenWritingNull</c> policy renders this as <c>{}</c>, which
+/// the client's <c>SetColosseumOwnStatus</c> short-circuits with <c>status.Count != 0</c>.
+/// </summary>
+[MessagePackObject]
+public class ColosseumOwnStatus
+{
+    [JsonPropertyName("rest_entry_num")] [Key("rest_entry_num")]
+    public int? RestEntryNum { get; set; }
+
+    [JsonPropertyName("now_round_id")] [Key("now_round_id")]
+    public int? NowRoundId { get; set; }
+
+    [JsonPropertyName("next_round_id")] [Key("next_round_id")]
+    public int? NextRoundId { get; set; }
+
+    [JsonPropertyName("is_last_day")] [Key("is_last_day")]
+    public bool? IsLastDay { get; set; }
+
+    [JsonPropertyName("is_champion")] [Key("is_champion")]
+    public bool? IsChampion { get; set; }
+
+    /// <summary>Only present when <see cref="IsChampion"/> is true — client uses it to overwrite
+    /// <c>ColosseumData.Name</c> for the champion screen.</summary>
+    [JsonPropertyName("colosseum_name")] [Key("colosseum_name")]
+    public string? ColosseumName { get; set; }
+}

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/ColosseumUserDeck.cs

@@ -0,0 +1,26 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
+
+/// <summary>Lightweight deck-info shape for <c>/top</c>'s <c>user_deck[0]</c>. The client's
+/// <c>DeckData.Initialize</c> consumes the canonical deck shape; this is the minimum needed
+/// to render the deck preview in Phase 1.</summary>
+[MessagePackObject]
+public class ColosseumUserDeck
+{
+    [JsonPropertyName("deck_id")] [Key("deck_id")]
+    public long DeckId { get; set; }
+
+    [JsonPropertyName("class_id")] [Key("class_id")]
+    public int ClassId { get; set; }
+
+    [JsonPropertyName("card_list")] [Key("card_list")]
+    public List<long> CardList { get; set; } = new();
+
+    [JsonPropertyName("sleeve_id")] [Key("sleeve_id")]
+    public long? SleeveId { get; set; }
+
+    [JsonPropertyName("skin_id")] [Key("skin_id")]
+    public long? SkinId { get; set; }
+}