fix: release beds/lockers in batchCheckOut

The batchCheckOut method was not releasing assigned beds and lockers
after checkout, leaving them orphaned as 'occupied'. Added the same
release pattern used in checkOut() — using runner.manager.update()
since batchCheckOut operates inside a QueryRunner transaction.

apps/server/src/classes/dto/class.dto.ts

@@ -98,6 +98,10 @@ export class QueryClassDto {
 
   @IsOptional() @IsString()
   keyword?: string;
+
+  @IsOptional()
+  @Type(() => Boolean)
+  isArchived?: boolean;
 }
 
 export class AddStudentsDto {