chore: cache catalogs for 6 hours

Author: TimilsinaBimal

app/api/endpoints/catalogs.py

@@ -193,8 +193,7 @@ def _get_limits() -> tuple[int, int]:
             logger.info(f"Found {len(recommendations)} recommendations for {type}")
 
         logger.info(f"Returning {len(recommendations)} items for {type}")
-        # Avoid serving stale results; revalidate on each request
-        response.headers["Cache-Control"] = "no-cache"
+        response.headers["Cache-Control"] = "public, max-age=21600" # 6 hours
         cleaned = [_clean_meta(m) for m in recommendations]
         return {"metas": cleaned}