refactor(#60): Utilise errors when signing out

src/lib/components/SignOut.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { createEventDispatcher, onDestroy } from 'svelte';
 	import { basket, type Basket, type Item } from '$lib/stores/basket.js';
+	import { logger } from '$lib/utils/logger.js';
 
 	const dispatch = createEventDispatcher();
 
@@ -19,8 +20,15 @@
 	onDestroy(unsubscribe);
 
 	async function signOut() {
-		// TODO use the error from the response
-		const { error } = await supabase.auth.signOut().then(() => {
+		const { error } = await supabase.auth.signOut();
+
+		if (error) {
+			logger.error('Error signing out:', error.message);
+			alert('Error signing out');
+			return;
+		}
+
+		try {
 			emitSignedOutEvent();
 
 			// Clear the basket
@@ -30,7 +38,10 @@
 			if (typeof localStorage !== 'undefined') {
 				localStorage.removeItem('basket');
 			}
-		});
+		} catch (err) {
+			logger.error('Error clearing basket:', err);
+			alert('Error clearing basket');
+		}
 	}
 </script>