该接口用于查询指定证券账号的当前股票持仓详情。通过传入证券账号 account_no,可选传入币种 currency 进行筛选,返回各持仓标的的数量、成本价、最新价、当日买卖金额等详细信息。需注意 该接口仅返回多头股票持仓,不包含空头及其他资产类型。This interface is used to query the current stock holding details of a specified securities account. By providing the account number account_no and an optional currency filter currency, it returns detailed information for each holding, including position quantity, cost price, latest price, and today's buy/sell amounts. Note that this interface only returns long stock positions, excluding short positions and other asset types.