fix: add back setup page

frontend/src/routes/login/setup/+page.svelte

@@ -0,0 +1,50 @@
+<script lang="ts">
+	import { goto } from '$app/navigation';
+	import SignInWrapper from '$lib/components/login-wrapper.svelte';
+	import { Button } from '$lib/components/ui/button';
+	import UserService from '$lib/services/user-service';
+	import appConfigStore from '$lib/stores/application-configuration-store.js';
+	import userStore from '$lib/stores/user-store.js';
+	import { getAxiosErrorMessage } from '$lib/utils/error-util';
+	import LoginLogoErrorSuccessIndicator from '../components/login-logo-error-success-indicator.svelte';
+
+	let isLoading = $state(false);
+	let error: string | undefined = $state();
+
+	const userService = new UserService();
+
+	async function authenticate() {
+		isLoading = true;
+		try {
+			const user = await userService.exchangeOneTimeAccessToken('setup');
+			userStore.setUser(user);
+
+			goto('/settings');
+		} catch (e) {
+			error = getAxiosErrorMessage(e);
+		}
+
+		isLoading = false;
+	}
+</script>
+
+<SignInWrapper>
+	<div class="flex justify-center">
+		<LoginLogoErrorSuccessIndicator error={!!error} />
+	</div>
+	<h1 class="font-playfair mt-5 text-4xl font-bold">
+		{`${$appConfigStore.appName} Setup`}
+	</h1>
+	{#if error}
+		<p class="text-muted-foreground mt-2">
+			{error}. Please try again.
+		</p>
+	{:else}
+		<p class="text-muted-foreground mt-2">
+			You're about to sign in to the initial admin account. Anyone with this link can access the
+			account until a passkey is added. Please set up a passkey as soon as possible to prevent
+			unauthorized access.
+		</p>
+		<Button class="mt-5" {isLoading} on:click={authenticate}>Continue</Button>
+	{/if}
+</SignInWrapper>