Add performance optimizations and component refactors

- Cache read-heavy public API routes via redisCache (leaderboard, values,
  shop, articles, photos, guilds, teams, staff, users, home, radio, badges)
- Add single-flight and bounded-memory cache layer with unit tests
- Parallelize independent DB queries on search, rares, shop, staff, polls
  and profile pages
- Push radio points leaderboard aggregation to SQL with a LIMIT
- Split studio-client and import-furni-client into focused modules
- Clean up next.config.ts

src/app/api/home/route.ts

@@ -3,7 +3,7 @@ import { apiJson } from "@/lib/api";
 import { FALLBACK_HOTEL_NAME } from "@/lib/brand";
 import { db, User, WebsiteArticles } from "@/lib/db";
 import { resolveHotelName } from "@/lib/hotel-name";
-import { apiCacheKey, redisCache } from "@/lib/redis-cache";
+import { apiCacheKey, cacheSafe, redisCache } from "@/lib/redis-cache";
 
 /**
  * GET /api/home — combined landing payload: the latest 4 website_articles and
@@ -29,7 +29,11 @@ export async function GET(_req: Request) {
 				db.select({ total: count() }).from(User).where(eq(User.online, "1")),
 				resolveHotelName(),
 			]);
-			return { articles, online: onlineRows[0]?.total ?? 0, hotelName };
+			return cacheSafe({
+				articles,
+				online: onlineRows[0]?.total ?? 0,
+				hotelName,
+			});
 		});
 		return apiJson(data);
 	} catch {