fix: add checksum

Author: HoonDongKang

.github/workflows/deploy-fe.yml

@@ -54,15 +54,17 @@ jobs:
             --exclude "index.html" \
             --delete \
             --acl public-read \
-            --cache-control "max-age=31536000, immutable"
+            --cache-control "max-age=31536000, immutable" \
+            --checksum-mode WHEN_REQUIRED
 
           # 2. index.html - 캐시 없음 (항상 최신 버전 유지)
           aws s3 sync frontend/dist/ s3://${{ secrets.NCP_BUCKET }}/ \
             --endpoint-url ${{ secrets.NCP_ENDPOINT }} \
             --exclude "*" \
             --include "index.html" \
             --acl public-read \
-            --cache-control "no-cache, no-store, must-revalidate"
+            --cache-control "no-cache, no-store, must-revalidate" \
+            --checksum-mode WHEN_REQUIRED
 
       - name: Deployment summary
         run: |