Account endpoints

Get current account balance with real-time updates. Multi-account support removed in v4.

Get current portfolio. Symbol field renamed, loginid parameter removed, and app_id can no longer be null.

Get profit/loss history. The loginid parameter removed, response fields now required, and app_id no longer nullable.

Get account statement. The loginid parameter removed, transfer-related fields removed, and action_type validation relaxed.

Subscribe to transaction notifications. Multiple fields removed, symbol renamed, and action enum validation removed.