우수 고객 확인 기능 추가하였습니다.

## 목적

## 작업 상세 내용
우수 고객 확인 기능 추가하였습니다.
## Reference

The issue title mentions adding a '우수 고객 확인 기능' (excellent customer verification feature) but provides no details on what changes are needed. Look for existing customer-related code or modules in the C++ project to understand the current structure. Determine where customer data is handled and what criteria define an 'excellent customer'. Check if there are any tests or documentation about customer features to guide implementation.

索引モデルが issue の本文から書いたものです。