feat: add salePrice field to Product model and update related files

- Added salePrice field to Product model in Prisma schema and generated files.
- Updated Product scalar field enums in both TypeScript files.
- Modified aggregate output types to include salePrice.
- Enhanced input types for creating and updating products to support salePrice.
- Updated migration file to add salePrice column to Products table.
- Created DTOs for inventory management in POS module.
- Implemented POS controller and service with methods for stock and product categories.

src/app.module.ts

@@ -5,6 +5,7 @@ import { CustomersModule } from './customers/customers.module'
 import { InventoriesModule } from './inventories/inventories.module'
 import { InventoryTransferItemsModule } from './inventory-transfer-items/inventory-transfer-items.module'
 import { InventoryTransfersModule } from './inventory-transfers/inventory-transfers.module'
+import { PosModule } from './pos/pos.module'
 import { PrismaModule } from './prisma/prisma.module'
 import { ProductBrandsModule } from './product-brands/product-brands.module'
 import { ProductCategoriesModule } from './product-categories/product-categories.module'
@@ -46,6 +47,7 @@ import { UsersModule } from './users/users.module'
     StockMovementsModule,
     StockAdjustmentsModule,
     StockBalanceModule,
+    PosModule,
   ],
   controllers: [AppController],
   providers: [AppService],