feat(pos): add POS controller and service for order creation and stock retrieval
refactor(pos): enhance stock and product category retrieval with pagination and mapping
- 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.
- Implemented CreateProductVariantDto and UpdateProductVariantDto for product variant data transfer.
- Developed ProductVariantsController to handle CRUD operations for product variants.
- Created ProductVariantsService to interact with the database using Prisma.
- Added ProductVariantsModule to encapsulate the product variant feature.
- Included response mapping for consistent API responses.
ahasani