fix: prevent pages transition on desktop

Author: grv-saini-20

platforms/metagram/src/routes/+layout.svelte

@@ -9,6 +9,9 @@
 
 	onNavigate((navigation) => {
 		if (!document.startViewTransition) return;
+		if (!window.matchMedia('(max-width: 768px)').matches) {
+		return;
+	}
 
 		const currentRoute = navigation.from?.url.pathname;
 		const targetRoute = navigation.to?.url.pathname;