Function parse_ws_cfm_account_state 

pub fn parse_ws_cfm_account_state(
    summary: &WsFcmBalanceSummary,
    account_id: AccountId,
    ts_event: UnixNanos,
    ts_init: UnixNanos,
) -> Result<AccountState>

Builds a margin [AccountState] from a WebSocket-delivered FCM balance summary.

The WebSocket payload does not carry explicit currency codes, so the balance is reported in USD (the only CFM settlement currency).

Errors

Returns an error when any component balance cannot be constructed.