feat: add discount amount to invoice response and display in invoice view

distribution_fe/lib/api/reports.ts

@@ -163,6 +163,7 @@ export const productReports = {
 export interface SalesKpis {
   grossSales: number
   returnValue: number
+  discounts: number
   netSales: number
   orders: number
   averageOrderValue: number
@@ -170,11 +171,19 @@ export interface SalesKpis {
   grossProfitMarginPercent: number | null
 }
 
+export interface CashKpis {
+  collected: number
+  outstanding: number
+  overdue: number
+  collectionRatePercent: number | null
+}
+
 export interface DashboardSalesSummary {
   from: string
   to: string
   granularity: 'day' | 'month'
   kpis: { current: SalesKpis; previous: SalesKpis; previousFrom: string; previousTo: string }
+  cash: { current: CashKpis; previous: CashKpis }
   trend: Array<{ period: string; sales: number; returns: number }>
   byCategory: Array<{ id: string | null; name: string; amount: number }>
   byRegion: Array<{ id: string | null; name: string; amount: number }>