feat: implement save receipt functionality with transaction handling and DTOs

backend/src/products/dto/update-product.dto.ts

@@ -1,9 +1,8 @@
-import { IsNotEmpty, IsNumber, IsOptional, IsString, MaxLength } from 'class-validator';
+import { IsNumber, IsOptional, IsString, MaxLength } from 'class-validator';
 
 export class UpdateProductDto {
   @IsOptional()
   @IsString()
-  @IsNotEmpty()
   @MaxLength(191)
   name?: string;
 
@@ -12,16 +11,6 @@ export class UpdateProductDto {
   @MaxLength(191)
   canonicalName?: string;
 
-  @IsOptional()
-  @IsString()
-  @MaxLength(191)
-  category?: string;
-
-  @IsOptional()
-  @IsString()
-  @MaxLength(191)
-  subcategory?: string;
-
   @IsOptional()
   @IsNumber()
   categoryId?: number | null;

backend/src/products/products.service.ts

@@ -188,10 +188,6 @@ export class ProductsService {
       updateData.canonicalName = data.canonicalName.trim() || undefined;
     }
 
-    if (typeof data.category === 'string') {
-      updateData.category = data.category.trim() || null;
-    }
-
     if ('categoryId' in data) {
       updateData.categoryId = data.categoryId ?? null;
     }