The blank-app-seed project has now been converted to a Simplified project structure and the old project structure is now referred to as Legacy. The permissions-app module is the server's main module and, as a minimum, is the only one required. All of the project's server code can be put in this module including configuration files, GPAL scripts and other Java/Kotlin code.
By default, the main module will be detected by a module ending with -app.
You can use the Genesis Gradle Settings plugin property mainModuleName to specify a custom name.
The Genesis Settings plugin is configured in server/settings.gradle.kts with the genesis extension.
For more details on project structures, see the docs.