[问题 | question]下拉菜单Dropdown中使用ModalForm，默认显示

### 🧐 问题描述 | Problem description

Dropdown的menu 是一个ModalForm 组件，默认显示open={true} 不生效

### 💻 示例代码 | Sample code

```js
export default () => {
const [form] = Form.useForm<{ name: string; company: string }>();
const [isOpen, setIsOpen] = useState(true); // 初始化为 true 以默认显示

const items: MenuProps["items"] = [
{
key: "1",
label: (

title="新建表单"
trigger={


新建表单

}
open={isOpen}
form={form}
autoFocusFirstInput
modalProps={{
destroyOnClose: true,
onCancel: () => setIsOpen(false),
}}
submitTimeout={2000}
onFinish={async (values) => {
setIsOpen(false); // 提交后关闭模态框
return true;
}}
>


),
},
];
return (

);
};
```

### 🚑 其他信息 | Other information

[在线demo](https://codesandbox.io/p/sandbox/modal-biao-dan-forked-dvzgfq?file=%2FApp.tsx%3A31%2C20&layout=%257B%2522sidebarPanel%2522%253A%2522EXPLORER%2522%252C%2522rootPanelGroup%2522%253A%257B%2522direction%2522%253A%2522horizontal%2522%252C%2522contentType%2522%253A%2522UNKNOWN%2522%252C%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522id%2522%253A%2522ROOT_LAYOUT%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522UNKNOWN%2522%252C%2522direction%2522%253A%2522vertical%2522%252C%2522id%2522%253A%2522clxttl38q0006356jbwueoncn%2522%252C%2522sizes%2522%253A%255B100%252C0%255D%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522EDITOR%2522%252C%2522direction%2522%253A%2522horizontal%2522%252C%2522id%2522%253A%2522EDITOR%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL%2522%252C%2522contentType%2522%253A%2522EDITOR%2522%252C%2522id%2522%253A%2522clxttl38q0002356jw3n29eou%2522%257D%255D%257D%252C%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522SHELLS%2522%252C%2522direction%2522%253A%2522horizontal%2522%252C%2522id%2522%253A%2522SHELLS%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL%2522%252C%2522contentType%2522%253A%2522SHELLS%2522%252C%2522id%2522%253A%2522clxttl38q0003356jrwc4i3vo%2522%257D%255D%252C%2522sizes%2522%253A%255B100%255D%257D%255D%257D%252C%257B%2522type%2522%253A%2522PANEL_GROUP%2522%252C%2522contentType%2522%253A%2522DEVTOOLS%2522%252C%2522direction%2522%253A%2522vertical%2522%252C%2522id%2522%253A%2522DEVTOOLS%2522%252C%2522panels%2522%253A%255B%257B%2522type%2522%253A%2522PANEL%2522%252C%2522contentType%2522%253A%2522DEVTOOLS%2522%252C%2522id%2522%253A%2522clxttl38q0005356jivpk4avf%2522%257D%255D%252C%2522sizes%2522%253A%255B100%255D%257D%255D%252C%2522sizes%2522%253A%255B50%252C50%255D%257D%252C%2522tabbedPanels%2522%253A%257B%2522clxttl38q0002356jw3n29eou%2522%253A%257B%2522tabs%2522%253A%255B%257B%2522id%2522%253A%2522clxttl38q0001356jiuse2m3y%2522%252C%2522mode%2522%253A%2522permanent%2522%252C%2522type%2522%253A%2522FILE%2522%252C%2522filepath%2522%253A%2522%252Findex.html%2522%252C%2522state%2522%253A%2522IDLE%2522%257D%252C%257B%2522id%2522%253A%2522clxtvnzlc0002356jjyh8plnl%2522%252C%2522mode%2522%253A%2522permanent%2522%252C%2522type%2522%253A%2522FILE%2522%252C%2522initialSelections%2522%253A%255B%257B%2522startLineNumber%2522%253A31%252C%2522startColumn%2522%253A20%252C%2522endLineNumber%2522%253A31%252C%2522endColumn%2522%253A20%257D%255D%252C%2522filepath%2522%253A%2522%252FApp.tsx%2522%252C%2522state%2522%253A%2522IDLE%2522%257D%255D%252C%2522id%2522%253A%2522clxttl38q0002356jw3n29eou%2522%252C%2522activeTabId%2522%253A%2522clxtvnzlc0002356jjyh8plnl%2522%257D%252C%2522clxttl38q0005356jivpk4avf%2522%253A%257B%2522id%2522%253A%2522clxttl38q0005356jivpk4avf%2522%252C%2522tabs%2522%253A%255B%257B%2522id%2522%253A%2522clxttl38q0004356js6r1rb2n%2522%252C%2522mode%2522%253A%2522permanent%2522%252C%2522type%2522%253A%2522UNASSIGNED_PORT%2522%252C%2522port%2522%253A0%252C%2522path%2522%253A%2522%252F%2522%257D%255D%252C%2522activeTabId%2522%253A%2522clxttl38q0004356js6r1rb2n%2522%257D%252C%2522clxttl38q0003356jrwc4i3vo%2522%253A%257B%2522tabs%2522%253A%255B%255D%252C%2522id%2522%253A%2522clxttl38q0003356jrwc4i3vo%2522%257D%257D%252C%2522showDevtools%2522%253Atrue%252C%2522showShells%2522%253Afalse%252C%2522showSidebar%2522%253Atrue%252C%2522sidebarPanelSize%2522%253A15%257D)

Reproduce the behavior in the linked CodeSandbox, starting with App.tsx and the ModalForm nested in the Dropdown menu. Check the initial open={isOpen} state and menu interaction; done means the expected default modal visibility is reproduced and the behavior is clarified or corrected.

Written by the indexing model from the issue text.