Add rate plans, room stay rates, and payments ledger

src/main/kotlin/com/android/trisolarisserver/repo/PaymentRepo.kt

@@ -0,0 +1,20 @@
+package com.android.trisolarisserver.repo
+
+import com.android.trisolarisserver.models.booking.Payment
+import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.data.jpa.repository.Query
+import org.springframework.data.repository.query.Param
+import java.util.UUID
+
+interface PaymentRepo : JpaRepository<Payment, UUID> {
+    fun findByBookingIdOrderByReceivedAtDesc(bookingId: UUID): List<Payment>
+
+    @Query(
+        """
+        select coalesce(sum(p.amount), 0)
+        from Payment p
+        where p.booking.id = :bookingId
+        """
+    )
+    fun sumAmountByBookingId(@Param("bookingId") bookingId: UUID): Long
+}