Tool for re-exporting types

If the project is a library, all `@typedef`s should be re-exported at the top level from `index.js`, if possible.

If the project is an app, the `@typedef`s should be made global (optionally).

Start by reading index.js and identifying how the project distinguishes a library from an app and where its @typedef definitions are handled. Confirm the intended top-level re-export behavior for libraries and optional global behavior for apps; the issue does not name tests or other files, so completion criteria need clarification.

索引モデルが issue の本文から書いたものです。