feat(meal-plan): add servings field to MealPlanEntry and update related functionality

feat(products): implement bulk update for product categories

feat(recipes): add servings input to WriteRecipePage and update MealPlanClient for servings management

refactor(types): enhance Product and Category types with additional properties

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

@@ -0,0 +1,12 @@
+import { IsArray, IsInt, IsNumber, IsOptional, ArrayMinSize } from 'class-validator';
+
+export class BulkUpdateProductsDto {
+  @IsArray()
+  @ArrayMinSize(1)
+  @IsInt({ each: true })
+  ids: number[];
+
+  @IsOptional()
+  @IsNumber()
+  categoryId?: number | null;
+}

backend/src/products/products.controller.ts

@@ -17,7 +17,7 @@ import { ProductsService } from './products.service';
 import { MergeProductsDto } from './dto/merge-products.dto';
 import { UpdateCanonicalNameDto } from './dto/update-canonical-name.dto';
 import { SetTagsDto } from './dto/set-tags.dto';
-import { UpsertNutritionDto } from './dto/upsert-nutrition.dto';
+import { BulkUpdateProductsDto } from './dto/bulk-update-products.dto';
 
 @Controller('products')
 export class ProductsController {
@@ -116,4 +116,10 @@ export class ProductsController {
   resetAll() {
     return this.productsService.resetAll();
   }
+
+  @Post('bulk-update')
+  @HttpCode(200)
+  bulkUpdate(@Body() body: BulkUpdateProductsDto) {
+    return this.productsService.bulkUpdate(body.ids, { categoryId: body.categoryId });
+  }
 }

backend/src/products/products.service.ts

@@ -397,4 +397,14 @@ export class ProductsService {
     ]);
     return { ok: true };
   }
+
+  async bulkUpdate(ids: number[], data: { categoryId?: number | null }) {
+    const updateData: Record<string, any> = {};
+    if ('categoryId' in data) {
+      updateData.categoryId = data.categoryId;
+    }
+    if (Object.keys(updateData).length === 0) return { updated: 0 };
+    await this.prisma.product.updateMany({ where: { id: { in: ids } }, data: updateData });
+    return { updated: ids.length };
+  }
 }