refactoring: TypeScript migration, security fixes,

client/src/utils/reorder.ts

@@ -0,0 +1,12 @@
+interface ItemWithId {
+  id: number
+  [key: string]: unknown
+}
+
+export function swapItems(items: ItemWithId[], index: number, direction: 'up' | 'down'): number[] | null {
+  const target = direction === 'up' ? index - 1 : index + 1
+  if (target < 0 || target >= items.length) return null
+  const ids = items.map((a) => a.id)
+  ;[ids[index], ids[target]] = [ids[target], ids[index]]
+  return ids
+}