test: 밸런스 분석 및 상수 테스트 추가

- balance_analysis_test 추가
- balance_constants_test 추가
- 기존 테스트 업데이트

test/features/game_play_screen_test.dart

@@ -89,7 +89,7 @@ GameSessionController _createController() {
     progressService: ProgressService(
       config: config,
       mutations: mutations,
-      rewards: RewardService(mutations),
+      rewards: RewardService(mutations, config),
     ),
     saveManager: _FakeSaveManager(),
     tickInterval: const Duration(seconds: 10), // 느린 틱

test/features/game_session_controller_test.dart

@@ -51,7 +51,7 @@ void main() {
   final progressService = ProgressService(
     config: config,
     mutations: mutations,
-    rewards: RewardService(mutations),
+    rewards: RewardService(mutations, config),
   );
 
   GameSessionController buildController(