Improve auction page loading and add a close button to guides

Optimizes auction data fetching with increased staleTime and implements a close button for the auction guide page by replacing the BookOpen icon with an X icon.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 9a264234-c5d7-4dcc-adf3-a954b149b30d
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/3df548ff-50ae-432f-9be4-25d34eccc983/9a264234-c5d7-4dcc-adf3-a954b149b30d/CMG42YQ

client/src/pages/AuctionGuide.tsx

@@ -8,7 +8,8 @@ import {
   Target,
   Gavel,
   Home,
-  BookOpen
+  BookOpen,
+  X
 } from "lucide-react";
 
 export default function AuctionGuide() {
@@ -32,28 +33,14 @@ export default function AuctionGuide() {
             </Link>
             
             <div className="flex items-center space-x-3">
-              <div className="relative">
-                <Button 
-                  variant="ghost" 
-                  size="sm"
-                  className="relative"
-                  onClick={handleGoBack}
-                  data-testid="button-auction-guide"
-                >
-                  <BookOpen className="h-4 w-4" />
-                </Button>
-                {/* Triangle indicator */}
-                <div className="absolute left-1/2 -translate-x-1/2 top-full z-10">
-                  <div 
-                    className="w-0 h-0 border-l-[12px] border-l-transparent border-r-[12px] border-r-transparent border-b-[10px] border-b-gray-50"
-                    style={{ filter: 'drop-shadow(0 -1px 0px rgba(229, 231, 235, 1))' }}
-                  />
-                </div>
-              </div>
-              
-              <a href="/api/login">
-                <Button size="sm" data-testid="button-login">Login</Button>
-              </a>
+              <Button 
+                variant="ghost" 
+                size="sm"
+                onClick={handleGoBack}
+                data-testid="button-close-guide"
+              >
+                <X className="h-5 w-5" />
+              </Button>
             </div>
           </div>
         </div>

client/src/pages/Auctions.tsx

@@ -99,10 +99,12 @@ export default function Auctions() {
 
   const { data: auctions = [], isLoading: auctionsLoading } = useQuery<Auction[]>({
     queryKey: ["/api/auctions"],
+    staleTime: 30000, // 30초 동안 캐시 유지
   });
 
   const { data: mediaOutlets = [] } = useQuery<MediaOutlet[]>({
     queryKey: ["/api/media-outlets"],
+    staleTime: 60000, // 1분 동안 캐시 유지
   });
 
   const bidMutation = useMutation({