feat: add "My Orders" link to navigation for authenticated users

Author: syandelbart

frontend/src/lib/components/navigation.svelte

@@ -20,6 +20,9 @@
 			<div class="bg-green-400 px-4 py-2">{name}</div>
 			<div class="bg-blue-400 px-4 py-2"><a href="/auth/logout">Logout</a></div>
 		{/if}
+		{#if authStore.isValid}
+			<div class="bg-blue-300 px-4 py-2"><a href="/orders">My Orders</a></div>
+		{/if}
 		<div class="bg-blue-400 px-4 py-2">
 			<a href="/order/cart">Cart ({cartStore.cart.length})</a>
 		</div>