ACATS transfer endpoints (Beta) added to the Broker API

Broker API

Adds Beta ACATS endpoints for initiating and tracking incoming account transfers, along with their supporting schemas.

Initiate an incoming transfer with contra account details, equities, and cash balance instructions.
List transfers across accounts or for a single account, with paging and sort direction.
Retrieve a single transfer, including status, DTCC status and transfer type, direction, account type, and rejection details.
List the assets and positions associated with a transfer.
List available contra brokers and their types.
On the ACATS equity request schema, prefer cusip for identifying securities; use symbol only when a CUSIP is unavailable, and supply one, not both.
The isin field on the ACATS asset schema is deprecated and will be removed on 2027-02-04. Use symbol or cusip instead.