Add promotion details and modal to orders and promotions

Introduces promotion-related fields to the Order interface and displays promotion discounts in both the order details and order table. Adds a PromotionDetailsModal component for viewing detailed promotion analytics and eligibility, and integrates it into the PromotionsList with a new 'view details' action.

components/tables/order-table.tsx

@@ -28,7 +28,9 @@ import {
   ArrowUpDown,
   Truck,
   MessageCircle,
-  AlertTriangle
+  AlertTriangle,
+  Tag,
+  Percent
 } from "lucide-react";
 import Link from "next/link";
 import { clientFetch } from '@/lib/api';
@@ -60,6 +62,11 @@ interface Order {
   underpaymentAmount?: number;
   lastBalanceReceived?: number;
   cryptoTotal?: number;
+  // Promotion fields
+  promotion?: string;
+  promotionCode?: string;
+  discountAmount?: number;
+  subtotalBeforeDiscount?: number;
 }
 
 type SortableColumns = "orderId" | "totalPrice" | "status" | "orderDate" | "paidAt";
@@ -430,6 +437,7 @@ export default function OrderTable() {
                   <TableHead className="cursor-pointer" onClick={() => handleSort("totalPrice")}>
                     Total <ArrowUpDown className="ml-2 inline h-4 w-4" />
                   </TableHead>
+                  <TableHead>Promotion</TableHead>
                   <TableHead className="cursor-pointer" onClick={() => handleSort("status")}>
                     Status <ArrowUpDown className="ml-2 inline h-4 w-4" />
                   </TableHead>
@@ -468,6 +476,29 @@ export default function OrderTable() {
                           )}
                         </div>
                       </TableCell>
+                      <TableCell>
+                        {order.promotionCode ? (
+                          <div className="flex flex-col gap-1">
+                            <div className="flex items-center gap-1">
+                              <Tag className="h-3 w-3 text-green-500" />
+                              <span className="text-xs font-mono bg-green-100 text-green-800 px-2 py-0.5 rounded">
+                                {order.promotionCode}
+                              </span>
+                            </div>
+                            <div className="flex items-center gap-1 text-xs text-green-600">
+                              <Percent className="h-3 w-3" />
+                              <span>-£{(order.discountAmount || 0).toFixed(2)}</span>
+                              {order.subtotalBeforeDiscount && order.subtotalBeforeDiscount > 0 && (
+                                <span className="text-muted-foreground">
+                                  (was £{order.subtotalBeforeDiscount.toFixed(2)})
+                                </span>
+                              )}
+                            </div>
+                          </div>
+                        ) : (
+                          <span className="text-xs text-muted-foreground">-</span>
+                        )}
+                      </TableCell>
                       <TableCell>
                         <div className="flex items-center gap-2">
                           <div className={`inline-flex items-center gap-2 px-3 py-1 rounded-full text-sm ${