update ui and other frontend updates

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

@@ -0,0 +1,35 @@
+<script lang="ts">
+	let { form } = $props();
+	let email = $state('');
+	let password = $state('');
+</script>
+
+<h1>Log in</h1>
+
+<form method="POST">
+	{#if form?.error}
+		<p class="error">{form.error}</p>
+	{/if}
+
+	<label>
+		Email
+		<input type="email" name="email" bind:value={email} required />
+	</label>
+
+	<label>
+		Password
+		<input type="password" name="password" bind:value={password} required />
+	</label>
+
+	<button type="submit">Log in</button>
+</form>
+
+<p>Don't have a family yet? <a href="/signup">Create one</a></p>
+
+<style>
+	form { display: flex; flex-direction: column; gap: 1rem; max-width: 400px; margin: 2rem auto; }
+	label { display: flex; flex-direction: column; gap: 0.25rem; }
+	input { padding: 0.5rem; border: 1px solid #ccc; border-radius: 4px; }
+	button { padding: 0.75rem; background: #6366f1; color: white; border: none; border-radius: 4px; cursor: pointer; }
+	.error { color: #dc2626; padding: 0.5rem; background: #fef2f2; border-radius: 4px; }
+</style>