docs(richtlinien): document why prerender=true is auth-safe

handleAuth in hooks.server.ts is in the sequence() chain and redirects
unauthenticated users at runtime regardless of prerender. Adding a comment
so the next reader doesn't mistake this for a security hole. (Markus/Nora)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/routes/hilfe/transkription/+page.ts

@@ -1 +1,6 @@
+// prerender = true is safe here: hooks.server.ts exports
+//   handle = sequence(userGroup, handleAuth, ...)
+// where handleAuth redirects all non-public paths to /login at runtime.
+// Prerendered HTML is served, but the browser still hits handleAuth on
+// every navigation — unauthenticated users are redirected before seeing content.
 export const prerender = true;