feat: 优化项目目录结构

apps/backend/src/admin/dto/common/pagination.dto.ts

@@ -0,0 +1,16 @@
+import { Type } from 'class-transformer';
+import { IsInt, IsOptional, Min } from 'class-validator';
+
+export class PaginationDto {
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(1)
+  page?: number = 1;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt()
+  @Min(1)
+  pageSize?: number = 20;
+}