refactor(products): remove subcategory from Product model and related queries

backend/src/products/products.controller.ts

@@ -42,9 +42,8 @@ export class ProductsController {
   @Get()
   findAll(
     @Query('tag') tag?: string,
-    @Query('subcategory') subcategory?: string,
   ) {
-    return this.productsService.findAll({ tag, subcategory });
+    return this.productsService.findAll({ tag });
   }
 
   @Public()