fix(ops): surface backend reason when system log cleanup is rejected

frontend/src/views/admin/ops/components/OpsSystemLogTable.vue

@@ -6,6 +6,7 @@ import { opsAPI, type OpsRuntimeLogConfig, type OpsSystemLog, type OpsSystemLogS
 import Pagination from '@/components/common/Pagination.vue'
 import Select from '@/components/common/Select.vue'
 import { useAppStore } from '@/stores'
+import { extractApiErrorMessage } from '@/utils/apiError'
 
 const appStore = useAppStore()
 const { t } = useI18n()
@@ -312,7 +313,11 @@ const cleanupCurrentFilter = async () => {
     await Promise.all([fetchLogs(), fetchHealth()])
   } catch (err: any) {
     console.error('[OpsSystemLogTable] Failed to cleanup logs', err)
-    appStore.showError(err?.response?.data?.detail || t('admin.ops.systemLogs.cleanupFailed'))
+    appStore.showError(
+      extractApiErrorMessage(err, t('admin.ops.systemLogs.cleanupFailed'), {
+        OPS_SYSTEM_LOG_CLEANUP_FILTER_REQUIRED: t('admin.ops.systemLogs.cleanupFilterRequired')
+      })
+    )
   }
 }