- Menu page: auto-scan ViewSet APIs for a selected menu, preview & batch
create MenuButton records with inline name/value editing, grouped table
- Role page: group button permissions by Model > CRUD intent (Read/Write/
Delete/Other) with expand/collapse, indeterminate checkboxes
- Backend: new batch_set_role_menu_btn action + value field in serializer
- Frontend: 300ms debounced batch updates to avoid DB lock on rapid toggles
- i18n: add scan.* keys and role intent labels for zh-cn/en/zh-tw
