Add drag-and-drop boss reordering and new feature beans

Adds boss battle reorder API endpoint with two-phase order update to
avoid unique constraint violations. Includes frontend mutation hook
and API client. Also adds draft beans for progression dividers and
conditional boss battle teams features.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/hooks/useAdmin.ts

@@ -16,6 +16,7 @@ import type {
   CreateBossBattleInput,
   UpdateBossBattleInput,
   BossPokemonInput,
+  BossReorderItem,
 } from '../types'
 
 // --- Queries ---
@@ -287,6 +288,18 @@ export function useUpdateBossBattle(gameId: number) {
   })
 }
 
+export function useReorderBosses(gameId: number) {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: (bosses: BossReorderItem[]) => adminApi.reorderBosses(gameId, bosses),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['games', gameId, 'bosses'] })
+      toast.success('Bosses reordered')
+    },
+    onError: (err) => toast.error(`Failed to reorder bosses: ${err.message}`),
+  })
+}
+
 export function useDeleteBossBattle(gameId: number) {
   const qc = useQueryClient()
   return useMutation({