Perf: cache Nitro client assets and parallelize client page

- Serve /swf and /nitro-assets (~2.8GB) with 7-day Cache-Control plus
  stale-while-revalidate so client opens stop re-fetching hundreds of
  files while asset updates still propagate in the background
- Issue the SSO ticket and the online count query in parallel on the
  client page to shave a round-trip off the critical render path

next.config.ts

@@ -125,6 +125,28 @@ const nextConfig: NextConfig = {
 					},
 				],
 			},
+			{
+				// Nitro client payload (~2.8GB across swf/nitro-assets): without
+				// caching every client open re-downloads hundreds of files.
+				// Fresh for 7 days, then serve stale + revalidate in background
+				// so asset updates still propagate without blocking players.
+				source: "/swf/(.*)",
+				headers: [
+					{
+						key: "Cache-Control",
+						value: "public, max-age=604800, stale-while-revalidate=2592000",
+					},
+				],
+			},
+			{
+				source: "/nitro-assets/(.*)",
+				headers: [
+					{
+						key: "Cache-Control",
+						value: "public, max-age=604800, stale-while-revalidate=2592000",
+					},
+				],
+			},
 			{
 				source: "/images/(.*)",
 				headers: [{ key: "Cache-Control", value: "public, max-age=86400" }],

src/app/client/page.tsx

@@ -21,15 +21,19 @@ export default async function ClientPage() {
 	]);
 
 	const ip = (await headers()).get("x-real-client-ip") ?? "0.0.0.0";
-	const ticket = await issueSsoTicket(userId, hotelName, ip);
 
-	const onlineCount = await cached("online_count", 10_000, async () => {
-		const [row] = await db
-			.select({ total: count() })
-			.from(User)
-			.where(eq(User.online, "1"));
-		return row?.total ?? 0;
-	}).catch(() => 0);
+	// Ticket write and online count run in parallel — the client page should
+	// render as fast as possible since the player is waiting for the game.
+	const [ticket, onlineCount] = await Promise.all([
+		issueSsoTicket(userId, hotelName, ip),
+		cached("online_count", 10_000, async () => {
+			const [row] = await db
+				.select({ total: count() })
+				.from(User)
+				.where(eq(User.online, "1"));
+			return row?.total ?? 0;
+		}).catch(() => 0),
+	]);
 
 	return (
 		<ClientView