Code Review

This pull request implements a reward system for battle completion and attendance marking, including the addition of reward history tracking. Key changes include updating BattleFinishService to grant cookies based on battle duration and result, and modifying MarkAttendanceService to record attendance rewards. The review feedback identifies critical race conditions in the reward granting logic where user balances are updated without database locks, which could lead to lost updates in concurrent environments. Additionally, there is a suggestion to improve the readability and consistency of the draw reward calculation.