feat(battle-engine): M1 auto-copy closure (782 battle-logic files)

Compile-driven bulk-copy loop (tools/engine-port/m1_copy_loop.py) pulled the precise reference closure of the battle-core roots, stopping at the classify god-object/View-VFX-UI boundary. 782 files; no re-explosion (M0 had estimated ~order 1000). Residual frontier = 52 shim-classified + 80 external (Unity/BCL) types to author next.

SVSim.BattleEngine/Engine/ICardCostModifier.cs

@@ -0,0 +1,12 @@
+public interface ICardCostModifier
+{
+	int Cost { get; }
+
+	bool IsClearBeforeModifier { get; }
+
+	bool IsResidentModifier { get; }
+
+	int CalcCost(int baseCost);
+
+	ICardCostModifier Clone();
+}