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.BattleNode/Sessions/Dispatch/Handlers/LoadedHandler.cs

@@ -22,8 +22,8 @@ internal sealed class LoadedHandler : IFrameHandler
             var r = new List<DispatchRoute>
             {
                 new(ctx.From, ServerBattleFrames.BuildBattleStart(
-                    ctx.From.Context, ctx.Other.Context, ctx.From.ViewerId, turnState), false),
-                new(ctx.From, ServerBattleFrames.BuildDeal(), false),
+                    ctx.From.Context, ctx.Other.Context, ctx.From.ViewerId, turnState), Stock.Normal),
+                new(ctx.From, ServerBattleFrames.BuildDeal(), Stock.Normal),
             };
             ctx.SenderPhase = BattleSessionPhase.AwaitingSwap;
             return r;