Further cleanup, mostly with svelte 5 migration placeholder cleanup

frontend/src/routes/+page.server.ts

@@ -3,8 +3,9 @@
 // SPDX-License-Identifier: MPL-2.0
 
 import { redirect } from '@sveltejs/kit';
+import type { PageServerLoad } from './$types';
 
-export const load = async ({ parent }) => {
+export const load: PageServerLoad = async ({ parent }) => {
 	const { email } = await parent();
 	if (email) {
 		redirect(302, '/dashboard');