perf: reduce apps cache TTL from 24h to 5min

HF Hub API rate limits allow up to 1000 requests per 5-minute window
for free users. With only 2 API calls per refresh, a 5-minute cache
is well within limits and ensures new community apps appear quickly.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/index.js

@@ -8,7 +8,7 @@ const app = express();
 const PORT = process.env.PORT || 7860;
 
 // Cache configuration
-const CACHE_TTL_MS = 24 * 60 * 60 * 1000; // 24 hours
+const CACHE_TTL_MS = 5 * 60 * 1000; // 5 minutes
 const OFFICIAL_APP_LIST_URL = 'https://huggingface.co/datasets/pollen-robotics/reachy-mini-official-app-store/raw/main/app-list.json';
 const HF_SPACES_API = 'https://huggingface.co/api/spaces';
 // Note: HF API doesn't support pagination with filter=, so we use a high limit