fix(buchhaltung): clean up tab labels, remove badge indicator, add session notification for pending transactions

frontend/src/components/dashboard/BuchhaltungPendingNotifier.tsx

@@ -0,0 +1,36 @@
+import { useEffect } from 'react';
+import { buchhaltungApi } from '../../services/buchhaltung';
+import { useNotification } from '../../contexts/NotificationContext';
+import { usePermissionContext } from '../../contexts/PermissionContext';
+
+const SESSION_KEY = 'buchhaltung-pending-notified';
+
+/**
+ * Invisible component — checks for pending (entwurf) transactions once per session
+ * and shows a notification toast if any exist.
+ */
+function BuchhaltungPendingNotifier() {
+  const { showNotificationToast } = useNotification();
+  const { hasPermission } = usePermissionContext();
+
+  useEffect(() => {
+    if (!hasPermission('buchhaltung:view')) return;
+    if (sessionStorage.getItem(SESSION_KEY)) return;
+
+    sessionStorage.setItem(SESSION_KEY, '1');
+
+    buchhaltungApi.getPendingCount().then(count => {
+      if (count > 0) {
+        showNotificationToast(
+          `${count} offene Buchung${count > 1 ? 'en' : ''} ausstehend`,
+          'warning',
+        );
+      }
+    }).catch(() => { /* ignore */ });
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  return null;
+}
+
+export default BuchhaltungPendingNotifier;