Extend order cancellation window for growers from 7 to 30 days

Currently, growers can cancel an order within 7 days. In practice, this window often turns out to be too short — especially when a product unexpectedly turns out to be sold out and this is only noticed later.

Several suppliers have indicated that in such cases they'd like to cancel the order and refund the reseller directly — but they can't, because the cancellation window has already expired.

Proposal: extend the cancellation window to 30 days, so growers can properly cancel in these situations and the reseller gets their money back right away.