New "total_amount" field on funding wallet transfers

Broker API

Adds the total_amount field to the FundingWalletTransfer schema.

• For outgoing transfers, total_amount is the total amount debited from the account (requested amount plus fees).
• For incoming transfers, total_amount is the requested amount.
• The original_amount field is deprecated and will be removed on 2026-12-21. Use total_amount for the actual amount debited from the account.

Affected Endpoints

• POST /v1beta/accounts/{account_id}/funding_wallet/withdrawal
• GET /v1beta/accounts/{account_id}/funding_wallet/transfers/{transfer_id}
• GET /v1beta/accounts/{account_id}/funding_wallet/transfers