Revert "fix(mpc-service): 添加 DTO 验证装饰器"

This reverts commit 6eb4b6b153.

backend/services/mpc-service/src/api/controllers/mpc.controller.ts

@@ -28,7 +28,6 @@ import {
   ApiResponse,
   ApiParam,
 } from '@nestjs/swagger';
-import { IsString, IsNumber, IsBoolean, IsOptional } from 'class-validator';
 import { Public } from '../../shared/decorators/public.decorator';
 import { MPCCoordinatorService } from '../../application/services/mpc-coordinator.service';
 
@@ -37,28 +36,15 @@ import { MPCCoordinatorService } from '../../application/services/mpc-coordinato
 // ============================================
 
 export class CreateKeygenDto {
-  @IsString()
   username: string;
-
-  @IsNumber()
   thresholdN: number;
-
-  @IsNumber()
   thresholdT: number;
-
-  @IsBoolean()
   requireDelegate: boolean;
 }
 
 export class CreateSigningDto {
-  @IsString()
   username: string;
-
-  @IsString()
   messageHash: string;
-
-  @IsString()
-  @IsOptional()
   userShare?: string;
 }