Update scheduling parameters and refactor channel endpoints: extend HorizonDays to 7 and RetentionDays to 90 in appsettings.json. Consolidate channel-related endpoint logic by removing obsolete files and enhancing the ShowEndpoints with audience and genre management capabilities. Improve error handling and streamline command handlers for channel operations.

frontend/src/features/admin/maintenance/MaintenancePanel.tsx

@@ -15,7 +15,7 @@ export function MaintenancePanel() {
   const queryClient = useQueryClient()
   const [showId, setShowId] = useState('')
 
-  const { data: shows } = useQuery({ queryKey: ['admin', 'shows'], queryFn: listShows })
+  const { data: shows } = useQuery({ queryKey: ['admin', 'shows'], queryFn: () => listShows() })
 
   const onError = (error: unknown) =>
     toast.error(error instanceof HttpError ? error.detail : t('common.error'))