fix(reminders): match Vorsorge page width to peer pages

The Vorsorge page wrapped its content in a centered max-w-2xl container
nested inside the shared app shell, rendering it noticeably narrower than
every peer surface. Drop the width cap and centering so the top-level
container is a bare space-y-6 div, matching measurements, labs,
medications, cycle, and mood.

src/app/vorsorge/page.tsx

@@ -24,7 +24,7 @@ export default function VorsorgePage() {
   }
 
   return (
-    <div className="mx-auto w-full max-w-2xl px-4 py-6">
+    <div className="space-y-6">
       <VorsorgeSection enabled={isAuthenticated} />
     </div>
   );