希望能新增Schema这个类，用于生成分层

如果有 Schema 可以实现 Schema.Domain 该方式

The issue proposes adding a Schema class so hierarchical generation can use an expression such as Schema.Domain, but it names no files, tests, or entry points. First map the generator's current model and output flow, then clarify the Schema API, supported hierarchy, and acceptance criteria before estimating implementation work.

索引モデルが issue の本文から書いたものです。