feat(ai): 优化拆解重跑与结果展示

apps/server/src/modules/ai/dto/decompose.dto.ts

@@ -1,4 +1,4 @@
-import { IsString, IsArray, ValidateNested, IsOptional } from 'class-validator';
+import { IsString, IsArray, ValidateNested, IsOptional, IsIn } from 'class-validator';
 import { Type } from 'class-transformer';
 
 export class DecomposeReqMemberDto {
@@ -34,6 +34,10 @@ export class DecomposeDto {
   @IsString()
   planId!: string;
 
+  @IsOptional()
+  @IsIn(['all', 'dev_tasks', 'test_cases'])
+  target?: 'all' | 'dev_tasks' | 'test_cases';
+
   @IsArray()
   @ValidateNested({ each: true })
   @Type(() => DecomposeReqRequirementDto)