Deal and Invoices lineitems sync

[DPorras]

Please add two-way synchronization between deal line items and invoice line items for unpaid/manual invoices. Today, when an invoice is created from a deal, the line items are copied only once and then become separate records. This creates manual work, causes mismatches between booking/deal amounts and invoice totals, and increases the risk of billing errors. We need updates made before payment, especially added or changed line items, to stay aligned between the deal and the invoice