refactor: resolve remaining field audit issues

apps/server/src/rooms/dto/room.dto.ts

@@ -1,4 +1,4 @@
-import { IsString, IsOptional, IsInt, IsEnum, Min, IsNumber } from 'class-validator';
+import { IsString, IsOptional, IsInt, IsEnum, IsIn, Min, IsNumber } from 'class-validator';
 
 export class CreateRoomDto {
   @IsString()
@@ -20,6 +20,10 @@ export class CreateRoomDto {
   @IsString()
   roomType?: string;
 
+  @IsOptional()
+  @IsIn(['男', '女'])
+  gender?: '男' | '女' | null;
+
   @IsOptional()
   @IsString()
   rentalCategory?: string;
@@ -27,7 +31,6 @@ export class CreateRoomDto {
   @IsOptional()
   @IsNumber()
   monthlyRate?: number;
-
 }
 
 export class UpdateRoomDto {
@@ -53,8 +56,8 @@ export class UpdateRoomDto {
   roomType?: string;
 
   @IsOptional()
-  @IsString()
-  gender?: string;
+  @IsIn(['男', '女'])
+  gender?: '男' | '女' | null;
 
   @IsOptional()
   @IsEnum(['available', 'full', 'maintenance'])