repoGitRoots

@get:Input
@get:Optional
abstract val repoGitRoots: ListProperty<String>

One entry per configured repo (index-aligned across the three lists), from repoLocations.dokkaRepoInfos — same data the diagram task uses. Lets function URLs resolve against EVERY repo (sourceRepo, stig-project stubs/harness, …) via the shared resolver, not just the element's repo.