分页：规范
定义了具有稳定排序、作用域不透明游标、有界页面大小、变更语义、错误处理和导航链接的游标分页，适用于偏移量漂移不可接受的 API。
Places client-specific aggregation, caching, and release coupling in a BFF layer while domain services stay client-agnostic, with explicit rules for what may not leak across the boundary.