fix first online resevation

apps/marketplace/src/lib/api.ts

@@ -29,3 +29,15 @@ export async function marketplaceFetchOrDefault<T>(path: string, fallback: T): P
     return fallback
   }
 }
+
+export async function marketplacePost<T>(path: string, body: unknown): Promise<T> {
+  const base = process.env.NEXT_PUBLIC_API_URL ?? 'http://localhost:4000/api/v1'
+  const res = await fetch(`${base}${path}`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify(body),
+  })
+  const json = await res.json().catch(() => null)
+  if (!res.ok) throw new MarketplaceApiError(json?.message ?? 'Request failed', res.status, json?.error)
+  return json.data as T
+}