refactor(battlenode): close §A boolean-blindness items (MinedToken, Stock, KeyActionType)

Behavior-preserving; 231 BattleNode tests green.

- MinedToken record struct replaces the transpose-prone (int Idx, long CardId,
  CardOwner IsSelf) tuple returned by KnownListBuilder.Mine*. Positional deconstruct
  keeps the Record*From call sites unchanged.
- enum Stock { Normal, Bypass } replaces the negative `bool noStock` on
  IBattleParticipant.PushAsync and DispatchRoute, threaded through both participants,
  BattleSession, and all handler construction sites.
- enum KeyActionType mirrors the client's SendKeyActionDataManager.KeyActionType;
  the StripKeyActionForOpponent guard compares named values, KeyActionEntry.Type is
  the enum (wire-identical via JsonNumberEnumConverter).

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

SVSim.UnitTests/BattleNode/Sessions/BattleSessionDispatchConcurrencyTests.cs

@@ -116,7 +116,7 @@ public class BattleSessionDispatchConcurrencyTests
         public Task RaiseAsync(MsgEnvelope env) =>
             FrameEmitted?.Invoke(env, CancellationToken.None) ?? Task.CompletedTask;
 
-        public Task PushAsync(MsgEnvelope env, bool noStock, CancellationToken ct) => _detector.EnterAsync();
+        public Task PushAsync(MsgEnvelope env, Stock stock, CancellationToken ct) => _detector.EnterAsync();
         public Task RunAsync(CancellationToken ct) => Task.CompletedTask;
         public Task TerminateAsync(BattleFinishReason reason) => Task.CompletedTask;
         public ValueTask DisposeAsync() => ValueTask.CompletedTask;