git commit -m "refactor: last20Messages aus _app.tsx entfernt und über Thunk in dashboard.tsx geladen"

services/fetchLast20Messages.ts

@@ -0,0 +1,9 @@
+export async function fetchLast20MessagesFromWindow(): Promise<string | null> {
+  return new Promise((resolve) => {
+    if (typeof window !== "undefined" && (window as any).win_last20Messages) {
+      resolve((window as any).win_last20Messages);
+    } else {
+      resolve(null);
+    }
+  });
+}