migrate auth v2 code

frontend/src/routes/+page.svelte

@@ -1,25 +1,5 @@
 <script lang="ts">
-	import { enhance } from '$app/forms';
 	import Footer from '$lib/components/Footer.svelte';
-	import type { Action, SubmitFunction } from './$types';
-
-	let email = $state('');
-	let password = $state('');
-	let famName = $state('');
-	let parentName = $state('');
-	let error = $state('');
-	let submitting = $state(false);
-
-	const submit: SubmitFunction = () => {
-		error = '';
-		submitting = true;
-		return async ({ result, update }) => {
-			if (result.type === 'failure') {
-				error = (result.data as any)?.error || 'Something went wrong. Please try again.';
-			}
-			submitting = false;
-		};
-	};
 </script>
 
 <svelte:head>
@@ -52,37 +32,7 @@
 			<div class="signup-card">
 				<h2>Start your family</h2>
 				<p class="card-sub">Free to get going. Takes about a minute.</p>
-				<form method="POST" action="/signup" use:enhance={submit}>
-					{#if error}
-						<p class="form-error">{error}</p>
-					{/if}
-					<label>
-						Family name
-						<input name="famName" bind:value={famName} placeholder="The Smiths" required />
-					</label>
-					<label>
-						Your name
-						<input name="parentName" bind:value={parentName} placeholder="Mum / Dad" required />
-					</label>
-					<label>
-						Email
-						<input type="email" name="email" bind:value={email} placeholder="you@email.com" required />
-					</label>
-					<label>
-						Password
-						<input
-							type="password"
-							name="password"
-							bind:value={password}
-							placeholder="8+ characters"
-							minlength={8}
-							required
-						/>
-					</label>
-					<button class="submit" type="submit" disabled={submitting}>
-						{submitting ? 'Creating your family…' : 'Create my family'}
-					</button>
-				</form>
+				<a class="submit" href="/signup">Create my family</a>
 				<p class="card-alt">
 					Already have a family? <a href="/login">Log in</a>
 				</p>
@@ -247,17 +197,20 @@
 		font-size: 0.85rem;
 		margin: 0;
 	}
-	.submit {
-		margin-top: 0.25rem;
-		background: #4338ca;
-		color: #fff;
-		border: none;
-		border-radius: 8px;
-		padding: 0.75rem;
-		font-size: 1rem;
-		font-weight: 600;
-		cursor: pointer;
-	}
+.submit {
+	display: block;
+	text-align: center;
+	margin-top: 0.25rem;
+	background: #4338ca;
+	color: #fff;
+	text-decoration: none;
+	border: none;
+	border-radius: 8px;
+	padding: 0.75rem;
+	font-size: 1rem;
+	font-weight: 600;
+	cursor: pointer;
+}
 	.submit:hover { background: #3730a3; }
 	.submit:disabled { opacity: 0.6; cursor: not-allowed; }
 	.card-alt { margin: 1rem 0 0; font-size: 0.85rem; color: #6b7280; text-align: center; }