Function plan 

pub fn plan(app: &App, targets: &[Target]) -> Result<Vec<Artifact>, Error>

Every artifact of the selected targets, from every source: the registry (OpenAPI, the reference, the registry manifest, the benchmark matrix), the schemas (allow-lists), the policy and the templates (provider bootstraps), and the registry with the index (the site dataset). This is the one plan generate writes and generate --check compares; nothing else assembles artifacts.