Add order items

internal/models/order.go

@@ -65,6 +65,7 @@ type PaymentOrderItem struct {
 	ID          uuid.UUID
 	PaymentID   uuid.UUID
 	OrderItemID uuid.UUID
+	Quantity    int // Quantity paid for this specific payment
 	Amount      float64
 	CreatedAt   time.Time
 	UpdatedAt   time.Time
@@ -114,6 +115,7 @@ type UpdateOrderRequest struct {
 
 type CreatePaymentOrderItemRequest struct {
 	OrderItemID uuid.UUID `validate:"required"`
+	Quantity    int       `validate:"required,min=1"` // Quantity being paid for
 	Amount      float64   `validate:"required,min=0"`
 }
 
@@ -205,12 +207,14 @@ type OrderItemResponse struct {
 	CreatedAt           time.Time
 	UpdatedAt           time.Time
 	PrinterType         string
+	PaidQuantity        int
 }
 
 type PaymentOrderItemResponse struct {
 	ID          uuid.UUID
 	PaymentID   uuid.UUID
 	OrderItemID uuid.UUID
+	Quantity    int // Quantity paid for this specific payment
 	Amount      float64
 	CreatedAt   time.Time
 	UpdatedAt   time.Time