refactor:centralize order status rules in shared package

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/shared/src/order-status.ts

@@ -1,3 +1,23 @@
 export const orderStatuses = ["pending", "processing", "shipped", "cancelled", "refunded"] as const;
 
 export type OrderStatus = (typeof orderStatuses)[number];
+
+const orderItemsEditableStatuses: readonly OrderStatus[] = ["pending"];
+const shippingAddressEditableStatuses: readonly OrderStatus[] = ["pending", "processing"];
+const orderCancellableStatuses: readonly OrderStatus[] = ["pending", "processing"];
+
+export const orderItemsLockedMessage = "Order items cannot be changed for this order status.";
+export const shippingAddressLockedMessage = "Shipping address cannot be changed for this order status.";
+export const orderCancellationBlockedMessage = "Order cannot be cancelled for this order status.";
+
+export function canEditOrderItems(status: OrderStatus) {
+  return orderItemsEditableStatuses.includes(status);
+}
+
+export function canEditShippingAddress(status: OrderStatus) {
+  return shippingAddressEditableStatuses.includes(status);
+}
+
+export function canCancelOrder(status: OrderStatus) {
+  return orderCancellableStatuses.includes(status);
+}