feat(account): add ability to sign in with login code (#271)

Co-authored-by: Elias Schneider <login@eliasschneider.com>

frontend/src/routes/login/alternative/code/+page.svelte

@@ -0,0 +1,74 @@
+<script lang="ts">
+	import { goto } from '$app/navigation';
+	import SignInWrapper from '$lib/components/login-wrapper.svelte';
+	import { Button } from '$lib/components/ui/button';
+	import Input from '$lib/components/ui/input/input.svelte';
+	import UserService from '$lib/services/user-service';
+	import userStore from '$lib/stores/user-store.js';
+	import { getAxiosErrorMessage } from '$lib/utils/error-util';
+	import { onMount } from 'svelte';
+	import LoginLogoErrorSuccessIndicator from '../../components/login-logo-error-success-indicator.svelte';
+	import { page } from '$app/state';
+
+	let { data } = $props();
+	let code = $state(data.code ?? '');
+	let isLoading = $state(false);
+	let error: string | undefined = $state();
+
+	const userService = new UserService();
+
+	async function authenticate() {
+		isLoading = true;
+		try {
+			const user = await userService.exchangeOneTimeAccessToken(code);
+			userStore.setUser(user);
+
+			try {
+				goto(data.redirect);
+			} catch (e) {
+				error = 'Invalid redirect URL';
+			}
+		} catch (e) {
+			error = getAxiosErrorMessage(e);
+		}
+
+		isLoading = false;
+	}
+
+	onMount(() => {
+		if (code) {
+			authenticate();
+		}
+	});
+</script>
+
+<svelte:head>
+	<title>Login Code</title>
+</svelte:head>
+
+<SignInWrapper>
+	<div class="flex justify-center">
+		<LoginLogoErrorSuccessIndicator error={!!error} />
+	</div>
+	<h1 class="font-playfair mt-5 text-4xl font-bold">Login Code</h1>
+	{#if error}
+		<p class="text-muted-foreground mt-2">
+			{error}. Please try again.
+		</p>
+	{:else}
+		<p class="text-muted-foreground mt-2">Enter the code you received to sign in.</p>
+	{/if}
+	<form
+		onsubmit={(e) => {
+			e.preventDefault();
+			authenticate();
+		}}
+		class="w-full max-w-[450px]"
+	>
+		<Input id="Email" class="mt-7" placeholder="Code" bind:value={code} type="text" />
+		<div class="mt-8 flex justify-stretch gap-2">
+			<Button variant="secondary" class="w-full" href={"/login/alternative" + page.url.search}>Go back</Button>
+			<Button class="w-full" type="submit" {isLoading}>Submit</Button>
+		</div>
+	</form>
+</SignInWrapper>