Method cleanup

packages/core/src/ECS/WorldManager.ts:342–360

* 清理空World

()

     * 清理空World
     */
    public cleanup(): number {
        const worldsToRemove: string[] = [];

        for (const [worldName, world] of this._worlds) {
            if (this.shouldCleanupWorld(world)) {
                worldsToRemove.push(worldName);
            }
        }

        for (const worldName of worldsToRemove) {
            this.removeWorld(worldName);
        }

        if (worldsToRemove.length > 0) {
            logger.debug(`清理了 ${worldsToRemove.length} 个World`);
        }

        return worldsToRemove.length;
    }

    /**
     * 销毁WorldManager