Revert "Revert purchase order"

This reverts commit 657a201fc0.

internal/validator/purchase_order_validator_test.go

@@ -11,34 +11,26 @@ import (
 )
 
 func validCreatePurchaseOrderRequest() *contract.CreatePurchaseOrderRequest {
+	ingredientID := uuid.New()
+	quantity := 1.0
+	unitID := uuid.New()
+
 	return &contract.CreatePurchaseOrderRequest{
 		VendorID:        uuid.New(),
 		PONumber:        "PO-001",
 		TransactionDate: "2026-05-29",
 		Items: []contract.CreatePurchaseOrderItemRequest{
 			{
-				IngredientID:       uuid.New(),
+				IngredientID:       &ingredientID,
 				PurchaseCategoryID: uuid.New(),
-				Quantity:           1,
-				UnitID:             uuid.New(),
+				Quantity:           &quantity,
+				UnitID:             &unitID,
 				Amount:             1000,
 			},
 		},
 	}
 }
 
-func TestPurchaseOrderValidatorCreateRejectsMissingRawMaterialFields(t *testing.T) {
-	validator := NewPurchaseOrderValidator()
-	req := validCreatePurchaseOrderRequest()
-	req.Items[0].IngredientID = uuid.Nil
-
-	err, code := validator.ValidateCreatePurchaseOrderRequest(req)
-
-	require.Error(t, err)
-	require.Equal(t, constants.MissingFieldErrorCode, code)
-	require.Contains(t, err.Error(), "ingredient_id is required")
-}
-
 func TestPurchaseOrderValidatorCreateAllowsMissingDueDate(t *testing.T) {
 	validator := NewPurchaseOrderValidator()
 
@@ -73,31 +65,3 @@ func TestPurchaseOrderValidatorCreateRejectsDueDateBeforeTransactionDate(t *test
 	require.Equal(t, constants.MalformedFieldErrorCode, code)
 	require.Contains(t, err.Error(), "due_date must be after transaction_date")
 }
-
-func TestPurchaseOrderValidatorUpdateItemsRequireFullReplacementFields(t *testing.T) {
-	validator := NewPurchaseOrderValidator()
-	req := &contract.UpdatePurchaseOrderRequest{
-		Items: []contract.UpdatePurchaseOrderItemRequest{
-			{
-				PurchaseCategoryID: ptrUUID(uuid.New()),
-				Quantity:           ptrFloat64(1),
-				UnitID:             ptrUUID(uuid.New()),
-				Amount:             ptrFloat64(1000),
-			},
-		},
-	}
-
-	err, code := validator.ValidateUpdatePurchaseOrderRequest(req)
-
-	require.Error(t, err)
-	require.Equal(t, constants.MissingFieldErrorCode, code)
-	require.Contains(t, err.Error(), "ingredient_id is required")
-}
-
-func ptrUUID(id uuid.UUID) *uuid.UUID {
-	return &id
-}
-
-func ptrFloat64(value float64) *float64 {
-	return &value
-}