Clojure wrapper for the Google Forms API (v1).

Provides idiomatic Clojure functions for creating and managing Google Forms,
reading form responses, and updating form structure via batch updates.

Auth: use csl/scoped-delegated-credentials or csl/user-credentials with
the appropriate scope:
- FormsScopes/FORMS_BODY              (read + write forms)
- FormsScopes/FORMS_BODY_READONLY     (read-only access to forms)
- FormsScopes/FORMS_RESPONSES_READONLY (read-only access to responses)
- FormsScopes/DRIVE                   (full Drive access — forms are Drive files)
- FormsScopes/DRIVE_FILE              (only files used with this app)
- FormsScopes/DRIVE_READONLY          (read-only Drive access)

Form structure is modified exclusively through batch-update, which takes a
vector of request maps (kebab-case keys, coerced to camelCase internally).
Convenience builders (create-item-request, delete-item-request, etc.) return
plain Clojure maps for use with batch-update.

Responses are read-only — they are submitted by form respondents, not the API.

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

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