Grants or revokes client access to a saved shareable report. This is what makes a report openable at all: an ungranted report opens for nobody, including the account owner. After granting, the client opens the report URL, enters their email, and GSC Wizard emails them a login link. That self-serve sign-in only works once they hold a grant. Clients must already exist on the account: add them with create_report_client, find ids with list_report_clients. NOTE: unlike the web app's share dialog, this tool does NOT itself send a "report shared with you" notification. Either pass the recipient the report URL, or send the notification from Account > Shared Reports in GSC Wizard (https://tool.gscwizard.com/account/shared-reports), where each client has a Resend button. action "revoke" withdraws access. Granting is idempotent: a client who already had access stays granted and is reported as unchanged.