feat: implement POS order management system

- Added CreateOrderDto and CreateOrderItemDto for order creation.
- Developed PosOrdersController to handle order-related endpoints.
- Created PosOrdersService for business logic related to orders.
- Implemented PosOrdersWorkflow for order processing workflows.
- Established Prisma integration for database operations in orders.
- Introduced SalesInvoicesModule and related DTOs for sales invoice management.
- Enhanced SalesInvoicesService and SalesInvoicesWorkflow for invoice processing.

prisma/schema/stock.prisma

@@ -63,15 +63,25 @@ model StockAdjustment {
 model StockReservation {
   id          Int       @id @default(autoincrement())
   quantity    Decimal   @db.Decimal(10, 0)
-  expiresAt   DateTime  @db.Timestamp(0)
   createdAt   DateTime  @default(now()) @db.Timestamp(0)
   productId   Int
   inventoryId Int
   orderId     Int
   inventory   Inventory @relation(fields: [inventoryId], references: [id])
   product     Product   @relation(fields: [productId], references: [id])
+  order       Order     @relation(fields: [orderId], references: [id], onDelete: Cascade)
 
   @@index([inventoryId])
   @@index([productId])
   @@map("Stock_Reservations")
 }
+
+view StockAvailableView {
+  productId         Int
+  inventoryId       Int
+  physicalQuantity  Decimal @db.Decimal(10, 0)
+  reservedQuantity  Decimal @db.Decimal(10, 0)
+  availableQuantity Decimal @db.Decimal(10, 0)
+
+  @@map("Stock_Available_View")
+}