feat(#9): Add sign up

src/routes/+layout.ts

@@ -0,0 +1,34 @@
+import { PUBLIC_SUPABASE_ANON_KEY, PUBLIC_SUPABASE_URL } from '$env/static/public';
+import type { LayoutLoad } from './$types';
+import { createBrowserClient, isBrowser, parse } from '@supabase/ssr';
+
+export const load: LayoutLoad = async ({ fetch, data, depends }) => {
+	depends('supabase:auth');
+
+	const supabase = createBrowserClient(PUBLIC_SUPABASE_URL, PUBLIC_SUPABASE_ANON_KEY, {
+		global: {
+			fetch
+		},
+		cookies: {
+			get(key) {
+				if (!isBrowser()) {
+					return JSON.stringify(data.session);
+				}
+
+				const cookie = parse(document.cookie);
+				return cookie[key];
+			}
+		}
+	});
+
+	/**
+	 * It's fine to use `getSession` here, because on the client, `getSession` is
+	 * safe, and on the server, it reads `session` from the `LayoutData`, which
+	 * safely checked the session using `safeGetSession`.
+	 */
+	const {
+		data: { session }
+	} = await supabase.auth.getSession();
+
+	return { supabase, session };
+};