add quantity to combobox

apps/admin.saladeaula.digital/app/routes/_.$orgid.enrollments.seats/route.tsx

@@ -90,15 +90,23 @@ export default function Route({ loaderData: { seats } }: Route.ComponentProps) {
     () =>
       Promise.resolve({
         hits: Array.from(
-          new Map(
-            seats.map(({ course }) => [
-              course.id,
-              {
-                ...course,
-                metadata__unit_price: 1
+          seats
+            .reduce((map, { course }) => {
+              const existing = map.get(course.id)
+
+              if (existing) {
+                existing.quantity += 1
+              } else {
+                map.set(course.id, {
+                  ...course,
+                  metadata__unit_price: 1,
+                  quantity: 1
+                })
               }
-            ]) ?? []
-          ).values()
+
+              return map
+            }, new Map())
+            .values()
         )
       }),
     [seats]