refactor: harden task authority and room mutations

src/core/redis/real_redis.service.ts

@@ -134,6 +134,18 @@ export class RealRedisService implements IRedisService, OnModuleDestroy {
     }
   }
 
+  async setIfAbsent(key: string, value: string, ttl?: number): Promise<boolean> {
+    try {
+      const result = ttl && ttl > 0
+        ? await this.redis.set(key, value, 'EX', ttl, 'NX')
+        : await this.redis.set(key, value, 'NX');
+      return result === 'OK';
+    } catch (error) {
+      this.logger.error(`原子设置Redis键失败: ${key}`, error);
+      throw error;
+    }
+  }
+
   /**
    * 获取键对应的值
    *