feat(race-class): Phase 5 종족/클래스 특화 시스템 구현

- RaceTraits: 7종족 (Byte Human, Null Elf, Buffer Dwarf 등)
- ClassTraits: 6클래스 (Bug Hunter, Compiler Mage 등)
- StatCalculator: 종족/클래스 보정 계산
- CombatStats.fromStats: 종족/클래스 패시브 효과 통합
- 종족별 스탯 보정 및 패시브 (경험치, HP/MP, 크리티컬 등)
- 클래스별 스탯 보정 및 패시브 (공격력, 방어력, 회피 등)

lib/data/race_data.dart

@@ -0,0 +1,167 @@
+import 'package:askiineverdie/src/core/model/race_traits.dart';
+
+/// 종족 데이터 정의 (race data)
+///
+/// 프로그래밍 테마의 7가지 종족 정의
+class RaceData {
+  RaceData._();
+
+  /// Byte Human: 균형형, 경험치 보너스
+  static const byteHuman = RaceTraits(
+    raceId: 'byte_human',
+    name: 'Byte Human',
+    statModifiers: {
+      StatType.cha: 2,
+    },
+    passives: [
+      PassiveAbility(
+        type: PassiveType.expBonus,
+        value: 0.10,
+        description: '경험치 +10%',
+      ),
+    ],
+    expMultiplier: 1.10,
+  );
+
+  /// Null Elf: 민첩/지능형, 마법 데미지 보너스
+  static const nullElf = RaceTraits(
+    raceId: 'null_elf',
+    name: 'Null Elf',
+    statModifiers: {
+      StatType.str: -1,
+      StatType.con: -1,
+      StatType.dex: 2,
+      StatType.intelligence: 2,
+    },
+    passives: [
+      PassiveAbility(
+        type: PassiveType.magicDamageBonus,
+        value: 0.15,
+        description: '마법 데미지 +15%',
+      ),
+    ],
+  );
+
+  /// Buffer Dwarf: 힘/체력형, 방어력 보너스
+  static const bufferDwarf = RaceTraits(
+    raceId: 'buffer_dwarf',
+    name: 'Buffer Dwarf',
+    statModifiers: {
+      StatType.str: 2,
+      StatType.con: 2,
+      StatType.dex: -1,
+      StatType.intelligence: -1,
+    },
+    passives: [
+      PassiveAbility(
+        type: PassiveType.defenseBonus,
+        value: 0.10,
+        description: '방어력 +10%',
+      ),
+    ],
+  );
+
+  /// Stack Goblin: 민첩형, 크리티컬 보너스
+  static const stackGoblin = RaceTraits(
+    raceId: 'stack_goblin',
+    name: 'Stack Goblin',
+    statModifiers: {
+      StatType.str: -1,
+      StatType.con: -1,
+      StatType.dex: 3,
+      StatType.cha: 1,
+    },
+    passives: [
+      PassiveAbility(
+        type: PassiveType.criticalBonus,
+        value: 0.05,
+        description: '크리티컬 확률 +5%',
+      ),
+    ],
+  );
+
+  /// Heap Troll: 체력형, HP 보너스
+  static const heapTroll = RaceTraits(
+    raceId: 'heap_troll',
+    name: 'Heap Troll',
+    statModifiers: {
+      StatType.str: 3,
+      StatType.con: 3,
+      StatType.dex: -2,
+      StatType.intelligence: -2,
+    },
+    passives: [
+      PassiveAbility(
+        type: PassiveType.hpBonus,
+        value: 0.20,
+        description: 'HP +20%',
+      ),
+    ],
+  );
+
+  /// Pointer Fairy: 마법형, MP 보너스
+  static const pointerFairy = RaceTraits(
+    raceId: 'pointer_fairy',
+    name: 'Pointer Fairy',
+    statModifiers: {
+      StatType.str: -2,
+      StatType.con: -2,
+      StatType.dex: 2,
+      StatType.intelligence: 2,
+      StatType.wis: 2,
+    },
+    passives: [
+      PassiveAbility(
+        type: PassiveType.mpBonus,
+        value: 0.20,
+        description: 'MP +20%',
+      ),
+    ],
+  );
+
+  /// Coredump Undead: 탱커형, 사망 시 장비 보존
+  static const coredumpUndead = RaceTraits(
+    raceId: 'coredump_undead',
+    name: 'Coredump Undead',
+    statModifiers: {
+      StatType.str: 1,
+      StatType.con: 2,
+      StatType.dex: -1,
+      StatType.cha: -2,
+    },
+    passives: [
+      PassiveAbility(
+        type: PassiveType.deathEquipmentPreserve,
+        value: 1.0,
+        description: '사망 시 장비 1개 유지',
+      ),
+    ],
+  );
+
+  /// 모든 종족 목록
+  static const List<RaceTraits> all = [
+    byteHuman,
+    nullElf,
+    bufferDwarf,
+    stackGoblin,
+    heapTroll,
+    pointerFairy,
+    coredumpUndead,
+  ];
+
+  /// ID로 종족 찾기
+  static RaceTraits? findById(String raceId) {
+    for (final race in all) {
+      if (race.raceId == raceId) return race;
+    }
+    return null;
+  }
+
+  /// 이름으로 종족 찾기
+  static RaceTraits? findByName(String name) {
+    for (final race in all) {
+      if (race.name == name) return race;
+    }
+    return null;
+  }
+}