feat: add product variant management functionality

- 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.

package.json

@@ -7,6 +7,8 @@
     "@nestjs/swagger": "^11.2.3",
     "@prisma/adapter-mariadb": "^7.1.0",
     "@prisma/client": "^7.1.0",
+    "class-transformer": "^0.5.1",
+    "class-validator": "^0.14.3",
     "dotenv": "^17.2.3",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1"
@@ -36,6 +38,7 @@
     "ts-loader": "^9.5.2",
     "ts-node": "^10.9.2",
     "tsconfig-paths": "^4.2.0",
+    "tsx": "^4.21.0",
     "typescript": "^5.7.3",
     "typescript-eslint": "^8.20.0"
   },
@@ -62,6 +65,7 @@
   "scripts": {
     "build": "nest build",
     "format": "prettier --write \"src/**/*.ts\" \"test/**/*.ts\"",
+    "generate:permissions": "tsx scripts/generate-permissions.ts",
     "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
     "start": "nest start",
     "start:debug": "nest start --debug --watch",