Polls the claim ceremony with grant_type=urn:workos:agent-auth:grant-type:claim.
Authenticate with the account API key (bearer, or the claim_token form field).
Returns authorization_pending until the human finishes, expired_token if the
code window closed, access_denied if the account was already claimed by someone
else, or a claimed success once bound. A human who already has an account gets
the agent account merged into it (balance and keys carry over), not a denial.
The API key keeps working after a successful claim.
Gateway API key (imp-rt-...) from POST /v1/accounts or /v1/keys.