Malaleem API

Test mode and live mode

A session takes the mode of the key that created it (`mk_test_…` or `mk_live_…`). A live session is paid only when the payment provider's verified notification arrives — never by anything the shopper's browser sends. Test sessions can also be completed by clearly-labelled simulations (a simulated card button, simulated Alipay / WeChat Pay / EBANX when those providers are not configured); a simulated payment moves no money and is refunded by simulation.