Interface B2S3Config

Configuration for deriving S3-compatible client settings from B2 auth state.

Per B2's S3-compatible API contract, the S3 accessKeyId is the applicationKeyId and the S3 secretAccessKey is the applicationKey. These are NOT the native accountId / authorizationToken returned by b2_authorize_account — those won't authenticate against the S3 endpoint. Both must be supplied here because AccountInfo doesn't retain the application key after authorization for security reasons.