Clojure wrapper for the Google Vault API (v1).

Provides idiomatic Clojure functions for eDiscovery and compliance workflows:
matters (cases), legal holds, exports, saved queries, and long-running
operations.

Auth: use csl/scoped-delegated-credentials or csl/user-credentials with the
appropriate scope. Note that the scope URL uses 'ediscovery', NOT 'vault':
- VaultScopes/EDISCOVERY          (full read/write — https://www.googleapis.com/auth/ediscovery)
- VaultScopes/EDISCOVERY_READONLY (read-only       — https://www.googleapis.com/auth/ediscovery.readonly)

Vault requires a Workspace plan that includes Vault (Business Plus,
Enterprise, Education Plus) and an admin role with eDiscovery privileges
(typically super-admin or a custom role granting Vault access).

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

Matters have a lifecycle distinct from CRUD: close-matter, reopen-matter, and
undelete-matter are POST operations that transition state and return the
updated matter.

count-matter-artifacts initiates a long-running Operation. Use
wait-for-operation to poll until completion.

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