feat(battlenode): attack resolves on engine state via view-untangle (M-HC-4a)

Drive ATTACK frames through the headless receive conductor and assert on engine
board state (node-native harness). Two cases: follower -> enemy leader (leader
life drops by atk, attacker spent) and a lethal follower-vs-follower trade (both
removed). ATTACK opcode confirmed = 10 (NetworkBattleDefine.PlayActionType).

Headless view-untangle (no Engine logic edits; drift clean):
- IBattlePlayerView.AttackSelectControl -> non-null HeadlessAttackSelectControl
  (no-op RegisterAttackPair/ResetCardAfterAttack); IsCardTranslatable left to base.
- IBattleCardView.CardInfo -> backing card via BuildInfo (so IsCardTranslatable
  reads authentic IsClass); class/null view ctors now chain : base(buildInfo).
- IBattleCardView._inPlayFrameEffect -> non-null no-op control.
- Seed Certification.viewer_id headless so the IsRecovery target parse
  (vid != UserViewerID) does not throw inside SavedataManager and silently drop
  the parsed targetList.

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

SVSim.BattleEngine/Shim/Generated/PlayerClassBattleCardView.g.cs

@@ -9,7 +9,7 @@ public partial class PlayerClassBattleCardView
         private readonly PlayerClassCharacter _classCharacter;
         public IClassCharacter ClassCharacter { get; set; }
         public float OriginalRootYPosition { get; set; }
-        public PlayerClassBattleCardView(BuildInfo buildInfo) { }
+        public PlayerClassBattleCardView(BuildInfo buildInfo) : base(buildInfo) { } // HEADLESS-FIX (M-HC-4a): chain BuildInfo so the leader view's CardInfo resolves (attack-on-leader targetting)
         public void StartOutFrame() { }
         public void StartIntoFrame() { }
         public float GetCurrentClipTime() => default!;