fix(rate-plans): the update DTO never allowed deactivation

apps/api/src/modules/rate-plan/dto/update-rate-plan.dto.ts

@@ -1,6 +1,19 @@
-import { PartialType, OmitType } from '@nestjs/swagger';
+import { PartialType, OmitType, ApiPropertyOptional } from '@nestjs/swagger';
+import { IsBoolean, IsOptional } from 'class-validator';
 import { CreateRatePlanDto } from './create-rate-plan.dto';
 
 export class UpdateRatePlanDto extends PartialType(
   OmitType(CreateRatePlanDto, ['propertyId', 'roomTypeId'] as const),
-) {}
+) {
+  /**
+   * Deactivation. The create DTO never carried isActive (it is a schema
+   * default), which left the API with NO way to retire a rate plan — the only
+   * lever was validTo, which expires a plan but keeps it active in every
+   * isActive-filtered list. Deliberately update-only: plans are created
+   * active, and retiring one is an explicit later act.
+   */
+  @ApiPropertyOptional({ description: 'Set false to deactivate the plan' })
+  @IsOptional()
+  @IsBoolean()
+  isActive?: boolean;
+}