Function build_manifest 

pub fn build_manifest(
    project_root: &Path,
    manifest: &Manifest,
    entry: &Path,
) -> Result<BuildManifest, CliError>

Assemble the linked closure for entry and describe it as a BuildManifest.

Every file the closure links is attributed to a dependency: a file rooted under a declared dependency’s root carries that dependency’s name; every other file (the project’s own src/) carries the local package name. This is the same assemble_closure seam every tier consumes, so the manifest describes exactly what the tiers link.