fix: Critical 버그 3건 수정

- death_handler: print() → debugPrint()로 변경 (프로덕션 성능)
- arena_combat_simulator: DOT 스킬 INT/WIS 실제 스탯 사용
- ad_service: iOS 광고 ID 플레이스홀더를 테스트 ID로 대체

lib/src/core/engine/death_handler.dart

@@ -1,3 +1,5 @@
+import 'package:flutter/foundation.dart';
+
 import 'package:asciineverdie/src/core/model/equipment_item.dart';
 import 'package:asciineverdie/src/core/model/equipment_slot.dart';
 import 'package:asciineverdie/src/core/model/game_state.dart';
@@ -104,8 +106,7 @@ class DeathHandler {
     final roll = state.rng.nextInt(100); // 0~99
     final shouldLoseEquipment = roll < lossChancePercent;
 
-    // ignore: avoid_print
-    print(
+    debugPrint(
       '[Death] Lv$level lossChance=$lossChancePercent% roll=$roll '
       'shouldLose=$shouldLoseEquipment',
     );
@@ -157,8 +158,7 @@ class DeathHandler {
       EquipmentItem.empty(lostItemSlot),
     );
 
-    // ignore: avoid_print
-    print('[Death] Lost item: ${lostItem.name} (slot: $lostItemSlot)');
+    debugPrint('[Death] Lost item: ${lostItem.name} (slot: $lostItemSlot)');
 
     return (
       equipment: newEquipment,