- departments->first() → department? (BelongsTo 단수 관계) - $emp->name → $emp->display_name - $emp->position → $emp->position_key - $emp->id → $emp->user_id - LeaveService에 department eager load 추가
- departments->first() → department? (BelongsTo 단수 관계) - $emp->name → $emp->display_name - $emp->position → $emp->position_key - $emp->id → $emp->user_id - LeaveService에 department eager load 추가