refactor(admin-charge): QGetChargeStatusQueryDto의 currency가 null이면 KRW로 설정되도록 coalesce("KRW") 적용

src/main/kotlin/kr/co/vividnext/sodalive/admin/charge/AdminChargeStatusQueryRepository.kt

@@ -36,7 +36,7 @@ class AdminChargeStatusQueryRepository(private val queryFactory: JPAQueryFactory
                     payment.price.sum(),
                     payment.id.count(),
                     payment.paymentGateway,
-                    currency.coalesce("")
+                    currency.coalesce("KRW")
                 )
             )
             .from(payment)
@@ -48,7 +48,7 @@ class AdminChargeStatusQueryRepository(private val queryFactory: JPAQueryFactory
                     .and(charge.status.eq(ChargeStatus.CHARGE))
                     .and(payment.status.eq(PaymentStatus.COMPLETE))
             )
-            .groupBy(formattedDate, payment.paymentGateway, currency.coalesce(""))
+            .groupBy(formattedDate, payment.paymentGateway, currency.coalesce("KRW"))
             .orderBy(formattedDate.desc())
             .fetch()
     }