fix:allow item quantity changes only for pending orders

apps/api/src/orders/order-status.ts

@@ -1,8 +1,6 @@
 import type { OrderStatus } from "@orderops/shared/order-status";
 
-export function canEditOrderItems(status: OrderStatus) {
-  return status === "pending";
-}
+export { canEditOrderItems } from "@orderops/shared/order-status";
 
 export function canEditShippingAddress(status: OrderStatus) {
   return status === "pending" || status === "processing";

apps/web/src/orders/order-items-panel.tsx

@@ -1,5 +1,5 @@
 import { useState } from "react";
-import type { OrderDetail } from "@orderops/shared";
+import { canEditOrderItems, type OrderDetail } from "@orderops/shared";
 
 interface OrderItemsPanelProps {
   order: OrderDetail;
@@ -9,10 +9,12 @@ interface OrderItemsPanelProps {
 function QuantityForm({
   itemId,
   quantity,
+  isEditable,
   onSave
 }: {
   itemId: string;
   quantity: number;
+  isEditable: boolean;
   onSave: (itemId: string, quantity: number) => Promise<void>;
 }) {
   const [value, setValue] = useState(String(quantity));
@@ -26,12 +28,17 @@ function QuantityForm({
       }}
     >
       <input
-        className="w-16 rounded-md border border-slate-300 px-2 py-1 text-sm"
+        className="w-16 rounded-md border border-slate-300 px-2 py-1 text-sm disabled:bg-slate-100 disabled:text-slate-500"
+        disabled={!isEditable}
         inputMode="numeric"
         value={value}
         onChange={(event) => setValue(event.target.value)}
       />
-      <button className="rounded-md bg-blue-600 px-3 py-1 text-sm font-medium text-white" type="submit">
+      <button
+        className="rounded-md bg-blue-600 px-3 py-1 text-sm font-medium text-white disabled:cursor-not-allowed disabled:bg-slate-300"
+        disabled={!isEditable}
+        type="submit"
+      >
         Save
       </button>
     </form>
@@ -39,9 +46,12 @@ function QuantityForm({
 }
 
 export function OrderItemsPanel({ order, onUpdateQuantity }: OrderItemsPanelProps) {
+  const isEditable = canEditOrderItems(order.status);
+
   return (
     <section className="rounded-xl border border-slate-200 bg-white p-4 shadow-sm">
       <h3 className="mb-3 text-sm font-semibold text-slate-700">Items</h3>
+      {isEditable ? null : <p className="mb-3 text-sm text-slate-500">Quantities can only be changed while the order is pending.</p>}
       <div className="space-y-3">
         {order.items.map((item) => (
           <div key={item.id} className="rounded-lg border border-slate-200 p-3">
@@ -51,7 +61,7 @@ export function OrderItemsPanel({ order, onUpdateQuantity }: OrderItemsPanelProp
                 <div className="text-sm text-slate-600">{item.sku}</div>
                 <div className="text-sm text-slate-500">Available: {item.availableQuantity}</div>
               </div>
-              <QuantityForm itemId={item.id} quantity={item.quantity} onSave={onUpdateQuantity} />
+              <QuantityForm itemId={item.id} quantity={item.quantity} isEditable={isEditable} onSave={onUpdateQuantity} />
             </div>
           </div>
         ))}

apps/web/src/orders/order-page.tsx

@@ -72,19 +72,6 @@ export function OrderPage() {
     }
   }
 
-  async function handleUpdateQuantity(itemId: string, quantity: number) {
-    if (!order) {
-      return;
-    }
-
-    if (order.status !== "pending") {
-      setToast({ message: "Order items cannot be changed for this order status.", variant: "error" });
-      return;
-    }
-
-    await runAction(() => updateOrderItemQuantity(order.id, itemId, quantity), "Quantity saved.");
-  }
-
   return (
     <div className="space-y-4">
       <Link className="inline-flex text-sm font-medium text-blue-600 hover:text-blue-700" to="/orders">
@@ -97,7 +84,7 @@ export function OrderPage() {
         <OrderDetailPage
           order={order}
           auditEvents={auditEvents}
-          onUpdateQuantity={handleUpdateQuantity}
+          onUpdateQuantity={(itemId, quantity) => runAction(() => updateOrderItemQuantity(order.id, itemId, quantity), "Quantity saved.")}
           onSaveAddress={(address: Address) => runAction(() => updateShippingAddress(order.id, address), "Shipping address saved.")}
           onSaveNotes={(notes) => runAction(() => updateOrderNotes(order.id, notes), "Notes saved.")}
           onCancel={() => runAction(() => cancelOrder(order.id), "Order cancelled.")}

packages/shared/src/order-status.ts

@@ -1,3 +1,9 @@
 export const orderStatuses = ["pending", "processing", "shipped", "cancelled", "refunded"] as const;
 
 export type OrderStatus = (typeof orderStatuses)[number];
+
+// Item quantities can only be adjusted before fulfillment starts. Shared so the UI
+// matches the API rule; the API stays the authoritative check.
+export function canEditOrderItems(status: OrderStatus) {
+  return status === "pending";
+}