Due date now derives from (scheduled send date else issue date) plus the
selected Net-days template, both in the editor and on save. The bill
editor renders it read-only with an Override toggle for manual entry;
existing invoices preserve their stored due date. Backend adds a single
resolveNetDays resolver that honors the split payment-net-days template
(previously only the legacy FK was read) and the
crm_payment_default_net_days setting, used by createInvoice and the
installment-spawn path alike.
Luca
522cf2aa4a