Feature: Add order tracking and shipping status updates

- Add carrier, trackingNumber, and estimatedDeliveryDate fields to Order model
- Update order statuses: PENDING, PAID, PRINTING, PRINTED, SHIPPED, DELIVERED, FAILED
- Add admin UI on order detail page to update tracking information
- Display tracking info on customer account page in order history
- Server action to update order tracking and status

Customers can now see their shipping status and tracking details from
their account page. Admins can update order status and tracking info
from the order detail page.

src/app/admin/orders/[id]/page.tsx

@@ -1,7 +1,7 @@
 import { notFound } from 'next/navigation';
 import { prisma } from '@/lib/prisma';
 import AdminNav from '@/components/AdminNav';
-import { archiveOrder, unarchiveOrder } from '../actions';
+import { archiveOrder, unarchiveOrder, updateOrderTracking } from '../actions';
 
 function formatPrice(cents: number) {
   return `£${(cents / 100).toFixed(2)}`;
@@ -76,6 +76,72 @@ export default async function OrderDetailPage({ params }: { params: { id: string
         )}
       </div>
 
+      {/* Tracking Information */}
+      <div className="mt-6 border border-line bg-surface p-6">
+        <h2 className="mb-4 font-display text-lg">Shipping & Tracking</h2>
+        <form action={updateOrderTracking} className="space-y-4">
+          <input type="hidden" name="orderId" value={order.id} />
+
+          <div className="grid gap-4 sm:grid-cols-2">
+            <div>
+              <label className="tag-label mb-1 block">Status</label>
+              <select
+                name="status"
+                defaultValue={order.status}
+                className="w-full border border-line bg-paper px-3 py-2 text-sm"
+              >
+                <option value="PENDING">PENDING</option>
+                <option value="PAID">PAID</option>
+                <option value="PRINTING">PRINTING</option>
+                <option value="PRINTED">PRINTED</option>
+                <option value="SHIPPED">SHIPPED</option>
+                <option value="DELIVERED">DELIVERED</option>
+                <option value="FAILED">FAILED</option>
+              </select>
+            </div>
+
+            <div>
+              <label className="tag-label mb-1 block">Carrier</label>
+              <input
+                type="text"
+                name="carrier"
+                defaultValue={order.carrier ?? ''}
+                placeholder="e.g. Royal Mail, DPD, Courier"
+                className="w-full border border-line bg-paper px-3 py-2 text-sm"
+              />
+            </div>
+
+            <div>
+              <label className="tag-label mb-1 block">Tracking Number</label>
+              <input
+                type="text"
+                name="trackingNumber"
+                defaultValue={order.trackingNumber ?? ''}
+                placeholder="e.g. RM123456789GB"
+                className="w-full border border-line bg-paper px-3 py-2 text-sm"
+              />
+            </div>
+
+            <div>
+              <label className="tag-label mb-1 block">Estimated Delivery Date</label>
+              <input
+                type="date"
+                name="estimatedDeliveryDate"
+                defaultValue={order.estimatedDeliveryDate ? new Date(order.estimatedDeliveryDate).toISOString().split('T')[0] : ''}
+                className="w-full border border-line bg-paper px-3 py-2 text-sm"
+              />
+            </div>
+          </div>
+
+          <button
+            type="submit"
+            className="bg-clay px-4 py-2 text-sm font-medium text-paper hover:bg-clay-dark"
+          >
+            Update Tracking Info
+          </button>
+        </form>
+      </div>
+
       <div className="mt-10 divide-y divide-line border-t border-line">
         {order.items.map((item) => {
           let hasFrontDesign = false;

src/app/admin/orders/actions.ts

@@ -35,3 +35,25 @@ export async function unarchiveOrder(formData: FormData) {
   await prisma.order.update({ where: { id }, data: { archived: false } });
   redirect('/admin/orders?archived=1');
 }
+
+export async function updateOrderTracking(formData: FormData) {
+  const id = String(formData.get('orderId') ?? '');
+  const status = String(formData.get('status') ?? 'PENDING');
+  const carrier = formData.get('carrier') ? String(formData.get('carrier')) : null;
+  const trackingNumber = formData.get('trackingNumber') ? String(formData.get('trackingNumber')) : null;
+  const estimatedDeliveryDate = formData.get('estimatedDeliveryDate') ? new Date(String(formData.get('estimatedDeliveryDate'))) : null;
+
+  if (!id) return;
+
+  await prisma.order.update({
+    where: { id },
+    data: {
+      status,
+      carrier,
+      trackingNumber,
+      estimatedDeliveryDate,
+    },
+  });
+
+  // TODO: Send email notification to customer when status changes
+}