fix: 修复批量更新账单状态功能

apps/server/src/bills/dto/bill.dto.ts

@@ -1,4 +1,4 @@
-import { IsString, IsOptional } from 'class-validator';
+import { ArrayNotEmpty, IsArray, IsIn, IsInt, IsString } from 'class-validator';
 
 export class GenerateBillsDto {
   @IsString()
@@ -9,6 +9,13 @@ export class GenerateBillsDto {
 }
 
 export class UpdateBillStatusDto {
-  @IsString()
+  @IsIn(['draft', 'confirmed', 'paid'])
   status: 'draft' | 'confirmed' | 'paid';
 }
+
+export class BatchUpdateBillStatusDto extends UpdateBillStatusDto {
+  @IsArray()
+  @ArrayNotEmpty()
+  @IsInt({ each: true })
+  ids: number[];
+}