feat(diet-records): 修复营养成分分析记录查询参数验证和类型转换

修复GET请求查询参数验证装饰器缺失问题，添加正确的class-validator装饰器
在控制器中实现查询参数类型转换，确保数字参数正确处理
更新技术文档，添加DTO验证装饰器编写规范和GET请求参数处理指南

src/diet-records/dto/nutrition-analysis-record.dto.ts

@@ -1,4 +1,5 @@
 import { ApiProperty } from '@nestjs/swagger';
+import { IsOptional, IsDateString, IsNumber, IsString } from 'class-validator';
 import { ApiResponseDto } from '../../base.dto';
 
 /**
@@ -98,17 +99,27 @@ export class NutritionAnalysisRecordsResponseDto extends ApiResponseDto<{
  */
 export class GetNutritionAnalysisRecordsQueryDto {
   @ApiProperty({ description: '页码', example: 1, required: false })
-  page?: number;
+  @IsOptional()
+  @IsString()
+  page?: string;
 
   @ApiProperty({ description: '每页数量', example: 20, required: false })
-  limit?: number;
+  @IsOptional()
+  @IsString()
+  limit?: string;
 
   @ApiProperty({ description: '开始日期', example: '2023-01-01', required: false })
+  @IsOptional()
+  @IsDateString()
   startDate?: string;
 
   @ApiProperty({ description: '结束日期', example: '2023-12-31', required: false })
+  @IsOptional()
+  @IsDateString()
   endDate?: string;
 
   @ApiProperty({ description: '分析状态', example: 'success', required: false })
+  @IsOptional()
+  @IsString()
   status?: string;
 }