fix: import ReactNode, Dispatch, SetStateAction explicitly (React namespace not in scope)

frontend/src/components/DataTable.tsx

@@ -1,3 +1,4 @@
+import { ReactNode } from 'react'
 import Table from '@mui/material/Table'
 import TableBody from '@mui/material/TableBody'
 import TableCell from '@mui/material/TableCell'
@@ -13,7 +14,7 @@ import Typography from '@mui/material/Typography'
 export interface Column<T> {
   key: keyof T
   label: string
-  render?: (row: T) => React.ReactNode
+  render?: (row: T) => ReactNode
 }
 
 interface Props<T extends { id: number }> {