better

cmd/cart/mutation_remove_item.go

@@ -21,29 +21,24 @@ import (
 //     semantics require pruning delivery.item_ids you can extend this handler.
 //   - If multiple lines somehow shared the same Id (should not happen), only
 //     the first match would be removed—data integrity relies on unique line Ids.
-func init() {
-	RegisterMutation[messages.RemoveItem](
-		"RemoveItem",
-		func(g *CartGrain, m *messages.RemoveItem) error {
-			if m == nil {
-				return fmt.Errorf("RemoveItem: nil payload")
-			}
-			targetID := int(m.Id)
 
-			index := -1
-			for i, it := range g.Items {
-				if it.Id == targetID {
-					index = i
-					break
-				}
-			}
-			if index == -1 {
-				return fmt.Errorf("RemoveItem: item id %d not found", m.Id)
-			}
+func RemoveItem(g *CartGrain, m *messages.RemoveItem) error {
+	if m == nil {
+		return fmt.Errorf("RemoveItem: nil payload")
+	}
+	targetID := int(m.Id)
 
-			g.Items = append(g.Items[:index], g.Items[index+1:]...)
-			return nil
-		},
-		WithTotals(),
-	)
+	index := -1
+	for i, it := range g.Items {
+		if it.Id == targetID {
+			index = i
+			break
+		}
+	}
+	if index == -1 {
+		return fmt.Errorf("RemoveItem: item id %d not found", m.Id)
+	}
+
+	g.Items = append(g.Items[:index], g.Items[index+1:]...)
+	return nil
 }