refactor(battle-node): de-magic wire flags and scattered constants

Quality pass from the 2026-06-04 BattleNode review (audit in the outer
repo). All changes are behavior-preserving — identical wire bytes,
verified by the full 1008-test suite staying green.

- Name scattered magic numbers: crypto key/IV lengths, outbound-sequencer
  base, WS receive buffer / EIO ping / SID length, polite-close timeout,
  upgrade-credential keys, battle-id digit math, deterministic-turn spin.
- resultCode = 1 -> (int)ReceiveNodeResultCode.Success across body records.
- Pong "3" -> EngineIoPacketType.Pong; remove dead NoOpBotParticipant.Touch
  (replace with #pragma warning disable CS0067).
- Wire-flag enums, serialized as numbers via JsonNumberEnumConverter:
  turnState -> TurnState{First,Second}, isSelf -> CardOwner{Opponent,Self},
  open -> ChoiceVisibility{Hidden,Open}.
- isOfficial / isInvoke -> bool / bool? via new NumericBoolJsonConverter
  (reads/writes 0/1; TDD'd). Scoped to the BattleNode wire boundary only;
  MatchContext and the HTTP/AI-start path stay int (AI-start uses -1 as a
  sentinel, so it is not boolean).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.BattleNode/Protocol/Bodies/AlivePushBody.cs

@@ -2,6 +2,10 @@ using System.Text.Json.Serialization;
 
 namespace SVSim.BattleNode.Protocol.Bodies;
 
+/// <summary>Gungnir keepalive push. <c>scs</c> = self connection status, <c>ocs</c> = opponent
+/// connection status; both carry <see cref="WireConstants.OnlineStatus"/> ("ONLINE") in v1.
+/// Intentionally has no <c>resultCode</c> — the client treats an absent resultCode on alive
+/// frames as "no error" (the lone body without one).</summary>
 public sealed record AlivePushBody(
     [property: JsonPropertyName("scs")] string Scs,
     [property: JsonPropertyName("ocs")] string Ocs) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/BattleFinishBody.cs

@@ -6,4 +6,4 @@ public sealed record BattleFinishBody(
     [property: JsonPropertyName("result")]
     [property: JsonConverter(typeof(JsonNumberEnumConverter<BattleResult>))]
     BattleResult Result,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/BattleStartBody.cs

@@ -3,11 +3,12 @@ using System.Text.Json.Serialization;
 namespace SVSim.BattleNode.Protocol.Bodies;
 
 public sealed record BattleStartBody(
-    [property: JsonPropertyName("turnState")] int TurnState,
+    [property: JsonPropertyName("turnState")]
+    [property: JsonConverter(typeof(JsonNumberEnumConverter<TurnState>))] TurnState TurnState,
     [property: JsonPropertyName("battleType")] int BattleType,
     [property: JsonPropertyName("selfInfo")] BattleStartSelfInfo SelfInfo,
     [property: JsonPropertyName("oppoInfo")] BattleStartOppoInfo OppoInfo,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;
 
 public sealed record BattleStartSelfInfo(
     [property: JsonPropertyName("rank")] string Rank,
@@ -18,6 +19,7 @@ public sealed record BattleStartSelfInfo(
 
 // Note: BattlePoint is int on the wire here (not string as on self) — matches the
 // captured prod frame at data_dumps/captures/battle-traffic_tk2_regular.ndjson.
+// The string-self / int-oppo split is INTENTIONAL; do NOT unify the two for "consistency".
 public sealed record BattleStartOppoInfo(
     [property: JsonPropertyName("rank")] string Rank,
     [property: JsonPropertyName("isMasterRank")] string IsMasterRank,

SVSim.BattleNode/Protocol/Bodies/DealBody.cs

@@ -5,4 +5,4 @@ namespace SVSim.BattleNode.Protocol.Bodies;
 public sealed record DealBody(
     [property: JsonPropertyName("self")] IReadOnlyList<PosIdx> Self,
     [property: JsonPropertyName("oppo")] IReadOnlyList<PosIdx> Oppo,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/JudgeBody.cs

@@ -2,6 +2,9 @@ using System.Text.Json.Serialization;
 
 namespace SVSim.BattleNode.Protocol.Bodies;
 
+/// <summary>Server-pushed Judge frame (turn-handover gate; reflected to the sender in PvP).
+/// Same wire shape as <see cref="OpponentTurnStartBody"/> — kept distinct because they back
+/// different frames/URIs.</summary>
 public sealed record JudgeBody(
     [property: JsonPropertyName("spin")] int Spin,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/MatchedBody.cs

@@ -6,8 +6,10 @@ public sealed record MatchedBody(
     [property: JsonPropertyName("selfInfo")] MatchedSelfInfo SelfInfo,
     [property: JsonPropertyName("oppoInfo")] MatchedOppoInfo OppoInfo,
     [property: JsonPropertyName("selfDeck")] IReadOnlyList<DeckCardRef> SelfDeck,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;
 
+// Note: `country_code` is deliberately snake_case among camelCase siblings — that's what prod
+// sends on this frame (verified against the TK2 capture). Do NOT "normalize" it to countryCode.
 public sealed record MatchedSelfInfo(
     [property: JsonPropertyName("country_code")] string CountryCode,
     [property: JsonPropertyName("userName")] string UserName,
@@ -15,7 +17,8 @@ public sealed record MatchedSelfInfo(
     [property: JsonPropertyName("emblemId")] string EmblemId,
     [property: JsonPropertyName("degreeId")] string DegreeId,
     [property: JsonPropertyName("fieldId")] int FieldId,
-    [property: JsonPropertyName("isOfficial")] int IsOfficial,
+    [property: JsonPropertyName("isOfficial")]
+    [property: JsonConverter(typeof(NumericBoolJsonConverter))] bool IsOfficial,
     [property: JsonPropertyName("oppoId")] long OppoId,
     [property: JsonPropertyName("seed")] long Seed);
 
@@ -26,7 +29,8 @@ public sealed record MatchedOppoInfo(
     [property: JsonPropertyName("emblemId")] string EmblemId,
     [property: JsonPropertyName("degreeId")] string DegreeId,
     [property: JsonPropertyName("fieldId")] int FieldId,
-    [property: JsonPropertyName("isOfficial")] int IsOfficial,
+    [property: JsonPropertyName("isOfficial")]
+    [property: JsonConverter(typeof(NumericBoolJsonConverter))] bool IsOfficial,
     [property: JsonPropertyName("oppoId")] long OppoId,
     [property: JsonPropertyName("seed")] long Seed,
     [property: JsonPropertyName("oppoDeckCount")] int OppoDeckCount);

SVSim.BattleNode/Protocol/Bodies/OpponentTurnStartBody.cs

@@ -2,6 +2,9 @@ using System.Text.Json.Serialization;
 
 namespace SVSim.BattleNode.Protocol.Bodies;
 
+/// <summary>Server-pushed opponent-turn-open frame (relayed to the non-active player).
+/// Same wire shape as <see cref="JudgeBody"/> — kept distinct because they back different
+/// frames/URIs.</summary>
 public sealed record OpponentTurnStartBody(
     [property: JsonPropertyName("spin")] int Spin,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/PlayActionsBroadcastBody.cs

@@ -32,7 +32,8 @@ public sealed record KeyActionEntry(
 /// Only emitted for the open:1 pass-through case (open:0 strips the whole <c>selectCard</c>).</summary>
 public sealed record SelectCardEntry(
     [property: JsonPropertyName("cardId")] IReadOnlyList<long> CardId,
-    [property: JsonPropertyName("open")] int Open);
+    [property: JsonPropertyName("open")]
+    [property: JsonConverter(typeof(JsonNumberEnumConverter<ChoiceVisibility>))] ChoiceVisibility Open);
 
 /// <summary>One revealed card in a <c>knownList</c>. Vanilla slice fills cardId from the sender's
 /// deck map and leaves spellboost 0 / attachTarget "" (cost/clan/tribe deferred to the card-master
@@ -48,7 +49,8 @@ public sealed record KnownCardEntry(
 /// verbatim — no perspective flip (bullet-3 audit F2).</summary>
 public sealed record OppoTargetEntry(
     [property: JsonPropertyName("targetIdx")] int TargetIdx,
-    [property: JsonPropertyName("isSelf")] int IsSelf);
+    [property: JsonPropertyName("isSelf")]
+    [property: JsonConverter(typeof(JsonNumberEnumConverter<CardOwner>))] CardOwner IsSelf);
 
 /// <summary>One entry in a relayed <c>uList</c> (the unapproved-movement list) — a skill-driven
 /// card movement (fetch / search / summon-from-deck / discard-reveal) the node forwards VERBATIM
@@ -60,12 +62,14 @@ public sealed record UnapprovedCardEntry(
     [property: JsonPropertyName("idxList")] IReadOnlyList<int> IdxList,
     [property: JsonPropertyName("from")] int From,
     [property: JsonPropertyName("to")] int To,
-    [property: JsonPropertyName("isSelf")] int IsSelf,
+    [property: JsonPropertyName("isSelf")]
+    [property: JsonConverter(typeof(JsonNumberEnumConverter<CardOwner>))] CardOwner IsSelf,
     [property: JsonPropertyName("skill")] string Skill,
     [property: JsonPropertyName("cardId")] long? CardId = null,
     [property: JsonPropertyName("clan")] int? Clan = null,
     [property: JsonPropertyName("cost")] int? Cost = null,
     [property: JsonPropertyName("skillKeyCardIdx")] IReadOnlyList<int>? SkillKeyCardIdx = null,
     [property: JsonPropertyName("randomTargetIdx")] IReadOnlyList<int>? RandomTargetIdx = null,
-    [property: JsonPropertyName("isInvoke")] int? IsInvoke = null,
+    [property: JsonPropertyName("isInvoke")]
+    [property: JsonConverter(typeof(NumericBoolJsonConverter))] bool? IsInvoke = null,
     [property: JsonPropertyName("attachTarget")] string? AttachTarget = null);

SVSim.BattleNode/Protocol/Bodies/ReadyBody.cs

@@ -7,4 +7,4 @@ public sealed record ReadyBody(
     [property: JsonPropertyName("oppo")] IReadOnlyList<PosIdx> Oppo,
     [property: JsonPropertyName("idxChangeSeed")] int IdxChangeSeed,
     [property: JsonPropertyName("spin")] int Spin,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/ResultCodeOnlyBody.cs

@@ -3,4 +3,4 @@ using System.Text.Json.Serialization;
 namespace SVSim.BattleNode.Protocol.Bodies;
 
 public sealed record ResultCodeOnlyBody(
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/SwapResponseBody.cs

@@ -4,4 +4,4 @@ namespace SVSim.BattleNode.Protocol.Bodies;
 
 public sealed record SwapResponseBody(
     [property: JsonPropertyName("self")] IReadOnlyList<PosIdx> Self,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/Bodies/TurnEndBody.cs

@@ -3,5 +3,6 @@ using System.Text.Json.Serialization;
 namespace SVSim.BattleNode.Protocol.Bodies;
 
 public sealed record TurnEndBody(
-    [property: JsonPropertyName("turnState")] int TurnState,
-    [property: JsonPropertyName("resultCode")] int ResultCode = 1) : IMsgBody;
+    [property: JsonPropertyName("turnState")]
+    [property: JsonConverter(typeof(JsonNumberEnumConverter<TurnState>))] TurnState TurnState,
+    [property: JsonPropertyName("resultCode")] int ResultCode = (int)ReceiveNodeResultCode.Success) : IMsgBody;

SVSim.BattleNode/Protocol/CardOwner.cs

@@ -0,0 +1,17 @@
+namespace SVSim.BattleNode.Protocol;
+
+/// <summary>
+/// Wire value of the actor-relative <c>isSelf</c> flag on relayed lists (<c>targetList</c>,
+/// <c>uList</c>): whose side a referenced card belongs to, from the SENDER's perspective. The node
+/// forwards it verbatim — no perspective flip (bullet-3 audit F2). The client reads it via
+/// <c>ConvertToInt(...) == 1</c> (<c>NetworkBattleReceiver.cs</c>), so it serializes as the
+/// underlying int via <see cref="System.Text.Json.Serialization.JsonNumberEnumConverter{T}"/>.
+/// </summary>
+public enum CardOwner
+{
+    /// <summary>Card belongs to the opponent of the sender.</summary>
+    Opponent = 0,
+
+    /// <summary>Card belongs to the sender.</summary>
+    Self = 1,
+}

SVSim.BattleNode/Protocol/ChoiceVisibility.cs

@@ -0,0 +1,17 @@
+namespace SVSim.BattleNode.Protocol;
+
+/// <summary>
+/// Wire value of <c>open</c> on a choice/Discover <c>selectCard</c>: whether the pick is revealed.
+/// The client emits it as <c>selectCardIsOpen ? 1 : 0</c> (<c>SendKeyActionDataManager.cs</c>);
+/// the node uses it to decide whether to strip the pick for the opponent (<c>Hidden</c> = strip).
+/// Serializes as the underlying int via
+/// <see cref="System.Text.Json.Serialization.JsonNumberEnumConverter{T}"/>.
+/// </summary>
+public enum ChoiceVisibility
+{
+    /// <summary>Hidden draw-to-hand pick — the chosen card stays secret until played.</summary>
+    Hidden = 0,
+
+    /// <summary>Visible board choice — the pick is revealed immediately.</summary>
+    Open = 1,
+}

SVSim.BattleNode/Protocol/NumericBoolJsonConverter.cs

@@ -0,0 +1,29 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace SVSim.BattleNode.Protocol;
+
+/// <summary>
+/// Serializes a <see cref="bool"/> as the wire's numeric 0/1. The client reads these flags via
+/// <c>Convert.ToInt32</c> / <c>Convert.ToBoolean</c> (e.g. <c>isOfficial</c>, <c>isInvoke</c>) —
+/// never as a JSON <c>true</c>/<c>false</c> token — so a real <c>bool</c> property must still emit
+/// a number. Read accepts a JSON number (0 = false, non-zero = true) and, defensively, a
+/// <c>true</c>/<c>false</c> token or a numeric string. Applied per-field via
+/// <c>[JsonConverter(typeof(NumericBoolJsonConverter))]</c>; works on <c>bool?</c> too (System.Text.Json
+/// wraps a <c>JsonConverter&lt;bool&gt;</c> for the nullable case).
+/// </summary>
+public sealed class NumericBoolJsonConverter : JsonConverter<bool>
+{
+    public override bool Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        => reader.TokenType switch
+        {
+            JsonTokenType.Number => reader.GetInt64() != 0,
+            JsonTokenType.True => true,
+            JsonTokenType.False => false,
+            JsonTokenType.String => long.TryParse(reader.GetString(), out var n) && n != 0,
+            _ => throw new JsonException($"Cannot convert token {reader.TokenType} to a numeric bool"),
+        };
+
+    public override void Write(Utf8JsonWriter writer, bool value, JsonSerializerOptions options)
+        => writer.WriteNumberValue(value ? 1 : 0);
+}

SVSim.BattleNode/Protocol/TurnState.cs

@@ -0,0 +1,16 @@
+namespace SVSim.BattleNode.Protocol;
+
+/// <summary>
+/// Wire value of <c>turnState</c> on BattleStart / TurnEnd frames: which side acts first.
+/// The client reads it via <c>Convert.ToInt32</c> (<c>RealTimeNetworkAgent.cs</c> "turnState"
+/// case) into <c>NetworkUserInfoData.TurnState</c>, so it serializes as the underlying int via
+/// <see cref="System.Text.Json.Serialization.JsonNumberEnumConverter{T}"/>.
+/// </summary>
+public enum TurnState
+{
+    /// <summary>This side takes the first turn.</summary>
+    First = 0,
+
+    /// <summary>This side takes the second turn.</summary>
+    Second = 1,
+}