KI-AGENT: Tabellen-Empty-States ohne JSON rendern

Ersetzt ungültige UTable-Empty-Props durch einen gemeinsamen Empty-State-Slot, damit leere Tabellen keine Objekt-/JSON-Ausgabe mehr anzeigen.

frontend/pages/accounting/cashbooks/index.vue

@@ -117,7 +117,6 @@ onMounted(loadCashbooks)
       class="w-full"
       :ui="{ divide: 'divide-gray-200 dark:divide-gray-800' }"
       :on-select="(row) => router.push(`/accounting/cashbooks/${row.original?.id || row.id}`)"
-      :empty="{ icon: 'i-heroicons-banknotes', label: 'Keine Kassenbücher angelegt' }"
   >
     <template #datevNumber-cell="{ row }">
       <span class="font-mono">{{ row.original.datevNumber }}</span>
@@ -128,6 +127,9 @@ onMounted(loadCashbooks)
     <template #syncedAt-cell="{ row }">
       {{ row.original.createdAt ? new Date(row.original.createdAt).toLocaleDateString("de-DE") : "-" }}
     </template>
+    <template #empty>
+      <TableEmptyState label="Keine Kassenbücher angelegt" icon="i-heroicons-banknotes" />
+    </template>
   </UTable>
 
   <UModal v-model:open="createCashbookModalOpen">