Add essential cookie notice and policy

src/lib/components/AppShell.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { page } from '$app/state';
 	import PendingForm from '$lib/components/PendingForm.svelte';
+	import { onMount } from 'svelte';
 	import type { Snippet } from 'svelte';
 
 	let { user, isacAccess, children }: {
@@ -14,6 +15,17 @@
 		{ href: '/builder', label: 'Builder' },
 		{ href: '/guides', label: 'Guides' }
 	];
+
+	let showCookieNotice = $state(false);
+
+	onMount(() => {
+		showCookieNotice = localStorage.getItem('shd-essential-cookie-notice') !== 'dismissed';
+	});
+
+	function dismissCookieNotice() {
+		localStorage.setItem('shd-essential-cookie-notice', 'dismissed');
+		showCookieNotice = false;
+	}
 </script>
 
 <header class="site-header">
@@ -45,6 +57,17 @@
 
 <footer class="site-footer">
 	<div><a class="brand footer-brand" href="/"><span class="brand-mark"><i></i><b>SHD</b></span><span>SHD<span class="accent">.build</span></span></a><p>Independent loadout intelligence for the agent community.</p></div>
-	<div class="footer-links"><a href="/terms">TERMS & PRIVACY</a><a href="/terms#retention">DATA RETENTION</a></div>
+	<div class="footer-links"><a href="/terms">TERMS & PRIVACY</a><a href="/terms#cookies">COOKIE POLICY</a><a href="/terms#retention">DATA RETENTION</a></div>
 	<p class="fan-disclaimer">UNOFFICIAL FAN SITE · NOT AFFILIATED WITH OR ENDORSED BY UBISOFT. TOM CLANCY’S THE DIVISION, THE DIVISION RESURGENCE, UBISOFT, AND RELATED INTELLECTUAL PROPERTY ARE OWNED BY UBISOFT AND/OR ITS LICENSORS.</p>
 </footer>
+
+{#if showCookieNotice}
+	<aside class="cookie-notice" aria-label="Essential cookie notice">
+		<div>
+			<p class="eyebrow"><span></span> ESSENTIAL SYSTEM NOTICE</p>
+			<p>SHD.build uses essential cookies for authentication and security. We do not use analytics or advertising cookies.</p>
+			<a href="/terms#cookies">VIEW COOKIE POLICY →</a>
+		</div>
+		<button type="button" onclick={dismissCookieNotice}>GOT IT</button>
+	</aside>
+{/if}