feat(F-189): completed feature

project/src/modules/pos/index.ts

@@ -7,7 +7,8 @@ export {
   type ValidatedPayment,
 } from './application/create-pos-sale.js';
 export { ReceiveRestPaymentUseCase } from './application/receive-rest-payment.js';
-export { buildPosReceipt } from './application/build-pos-receipt.js';
+export { ApplyPosReturnUseCase } from './application/apply-pos-return.js';
+export { buildPosReceipt, buildPosReturnReceipt } from './application/build-pos-receipt.js';
 export type {
   PosSaleInput,
   PosSaleResult,
@@ -15,5 +16,8 @@ export type {
   PosSaleLineItem,
   PosPaymentInput,
   PosPaymentResult,
+  PosReturnInput,
+  PosReturnResult,
+  PosReturnLineInput,
   PosReceipt,
 } from './domain/pos-sale.js';