add: local wishlists stored in local storage for anonymous users

src/lib/components/layout/DashboardHeader.svelte

@@ -8,16 +8,25 @@
 	let { userName, userEmail }: { userName?: string | null; userEmail?: string | null } = $props();
 
 	const t = $derived(languageStore.t);
+	const isAuthenticated = $derived(!!userName || !!userEmail);
 </script>
 
 <div class="flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
 	<div class="flex-1 min-w-0">
 		<h1 class="text-3xl font-bold">{t.nav.dashboard}</h1>
-		<p class="text-muted-foreground truncate">{t.dashboard.welcomeBack}, {userName || userEmail}</p>
+		{#if isAuthenticated}
+			<p class="text-muted-foreground truncate">{t.dashboard.welcomeBack}, {userName || userEmail}</p>
+		{:else}
+			<p class="text-muted-foreground">{t.dashboard.anonymousDashboard || "Your local wishlists"}</p>
+		{/if}
 	</div>
 	<div class="flex items-center gap-1 sm:gap-2 flex-shrink-0">
 		<LanguageToggle />
 		<ThemeToggle />
-		<Button variant="outline" onclick={() => signOut({ callbackUrl: '/' })}>{t.auth.signOut}</Button>
+		{#if isAuthenticated}
+			<Button variant="outline" onclick={() => signOut({ callbackUrl: '/' })}>{t.auth.signOut}</Button>
+		{:else}
+			<Button variant="outline" onclick={() => (window.location.href = '/signin')}>{t.auth.signIn}</Button>
+		{/if}
 	</div>
 </div>