feat: item-level discount

packages/webapp/src/containers/Drawers/BillDrawer/BillDetailTable.tsx

@@ -20,6 +20,10 @@ export default function BillDetailTable() {
     <CommercialDocEntriesTable
       columns={columns}
       data={entries}
+      initialHiddenColumns={
+        // If any entry has no discount, hide the discount column.
+        entries?.some((e) => e.discount_formatted) ? [] : ['discount']
+      }
       styleName={TableStyle.Constrant}
     />
   );