The only variable of the role was documented in defaults/main.yaml comments alone. An argument spec makes the variable
discoverable through ansible-doc and lets ansible reject a wrong type early.
The entries are intentionally left without suboptions. Argument spec validation fills missing suboptions with none,
which would turn the item.user | default('') | length conditions in tasks/main.yaml into a runtime error.
Co-authored-by: Copilot <copilot@github.com>
