perf(build): measure the homepage and fix optimizePackageImports

/ is the highest-traffic route but was missing from both the public-route
instrumentation and the JS size budgets, so a payload regression there could
never fail the build. It is now wrapped in withPublicPagePerformance and
budgeted alongside the other public routes.

optimizePackageImports listed date-fns, which is not a dependency (a no-op),
while omitting the barrel-heavy packages that are actually imported: motion,
@dnd-kit/core, @dnd-kit/sortable and @tanstack/react-virtual.

src/app/(site)/page.tsx

@@ -23,6 +23,7 @@ import { cached } from "@/lib/cache";
 import { CameraWeb, db, User } from "@/lib/db";
 import { formatDate } from "@/lib/format-date";
 import { resolveHotelName } from "@/lib/hotel-name";
+import { withPublicPagePerformance } from "@/lib/public-page-performance";
 import { captchaConfig } from "@/lib/services/captcha";
 import { getNewsList } from "@/lib/services/news-list";
 import { loadProfilePrivacyMap } from "@/lib/services/profile-privacy";
@@ -238,7 +239,7 @@ async function getHotelData() {
 	};
 }
 
-export default async function Home() {
+async function Home() {
 	const session = await auth();
 	if (session?.user?.id) redirect("/me");
 
@@ -1148,3 +1149,5 @@ export default async function Home() {
 		</div>
 	);
 }
+
+export default withPublicPagePerformance("/", Home);