Introduce AuthLoadingSkeleton and HeaderSkeleton for smoother loading, replace spinner in AuthGuard, update ReactQueryDevtools toggle, enable Docker ports for local development.

frontend/src/components/layout/index.ts

@@ -5,3 +5,5 @@
 
 export { Header } from './Header';
 export { Footer } from './Footer';
+export { HeaderSkeleton } from './HeaderSkeleton';
+export { AuthLoadingSkeleton } from './AuthLoadingSkeleton';