fix(frontend): disable prerender crawl so /, /documents, /persons aren't baked

Closes #514.

The build was prerendering protected routes via crawl from
/hilfe/transkription. Their load functions throw redirect('/login')
during the build (no auth cookie), so SvelteKit captured the redirect
as static HTML and shipped /app/build/prerendered/{index,documents,
persons,geschichten,stammbaum}.html with a `location.href=/login`
script. In production these files are served BEFORE hooks.server.ts
runs, so an authenticated user with a valid cookie is still served
the baked bounce-back page.

Setting `crawl: false` keeps the explicit /hilfe/transkription entry
prerendered (needed for the public help page) without dragging the
nav targets along with it.

Verified locally: build now emits only `hilfe/transkription.html`
under build/prerendered/, no index.html or documents.html etc.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/svelte.config.js

@@ -8,7 +8,17 @@ const config = {
 	preprocess: vitePreprocess(),
 	kit: {
 		adapter: adapter(),
-		prerender: { entries: ['/hilfe/transkription'] }
+		prerender: {
+			entries: ['/hilfe/transkription'],
+			// Disable crawl: by default SvelteKit follows nav links from
+			// prerendered pages and prerenders the targets too. The targets
+			// (/, /documents, /persons, …) throw redirect('/login') during
+			// the build (no auth cookie), so SvelteKit bakes a
+			// `<script>location.href='/login'</script>` HTML page and serves
+			// it before the runtime hooks ever run. Result: authenticated
+			// users with a valid cookie still get bounced. See #514.
+			crawl: false
+		}
 	}
 };