feat: integrate observability

apps/sample-website/src/app/stats/api/send/route.ts

@@ -0,0 +1,7 @@
+import { createUmamiProxyHandler } from "@mintel/next-observability";
+import { validateMintelEnv } from "@mintel/next-utils";
+
+export const POST = createUmamiProxyHandler({
+  websiteId: validateMintelEnv().UMAMI_WEBSITE_ID,
+  apiEndpoint: validateMintelEnv().UMAMI_API_ENDPOINT,
+});