Clojure wrapper for the Google Apps Licensing API.

Provides idiomatic Clojure functions for reading per-user Workspace
SKU assignments (Business Standard, Enterprise, Plus, etc.).

Auth: use csl/scoped-delegated-credentials with the appropriate scope
and a super-admin impersonation target:
- LicensingScopes/APPS_LICENSING  (read + write — see SCOPE NOTE below)

All list functions return {:data [...] :next-page-token "..."}.
:next-page-token is absent when there are no further pages.

SCOPE NOTE
`apps.licensing` is the only scope exposed by Google for this API;
it grants read + write. This wrapper only exposes list/get
(LicenseAssignments). Write counterparts (`insert`, `update`,
`delete`, `transfer`) are intentionally not wrapped here; a future
write consumer files its own FR.

Workspace product/SKU id strings (e.g. product "Google-Apps", SKU
"Google-Apps-For-Business") are documented externally by Google's
Workspace SKU catalog. The wrapper passes them through unchanged.

All functions return {:data ...} on success or {:error ...} on failure.