fix(ui): tune Toast live region semantics

docs/components/toast.md

@@ -7,19 +7,25 @@
 <LivePlayground :code="`
 () => {
   return (
-    <Space>
-      <Toast open status='success' duration={0}>操作成功</Toast>
-      <Toast open status='error' duration={0}>操作失败</Toast>
-    </Space>
+    <div className='flex flex-col gap-3'>
+      <Toast open status='success' duration={0} className='static'>操作成功</Toast>
+      <Toast open status='error' duration={0} className='static'>操作失败</Toast>
+    </div>
   )
 }
 `" />
 
+## 可访问性
+
+Toast 默认会把 `info`、`success`、`warning` 作为 `role="status"` 的礼貌通知呈现；`error` 默认作为 `role="alert"` 的紧急通知呈现。需要更细粒度控制时，可以显式传入 `role` 与 `aria-live`。
+
 ## API
 
 | 属性 | 说明 | 类型 | 默认值 |
 | --- | --- | --- | --- |
 | open | 是否显示 | `boolean` | `false` |
 | duration | 显示时长(ms)，0 表示不自动关闭 | `number` | `3000` |
 | status | 状态 | `'info' \| 'success' \| 'warning' \| 'error'` | `'info'` |
+| role | live region 语义，默认 error 为 alert，其余状态为 status | `'status' \| 'alert'` | - |
+| aria-live | live region 播报优先级，传入后覆盖默认值 | `'off' \| 'polite' \| 'assertive'` | - |
 | onClose | 关闭回调 | `() => void` | - |

packages/ui/src/components/feedback/Toast/Toast.test.tsx

@@ -17,6 +17,30 @@ describe('Toast', () => {
     expect(toast).toHaveTextContent('Saved successfully')
   })
 
+  it('renders error updates as alert regions', () => {
+    render(
+      <Toast open status="error">
+        Save failed
+      </Toast>,
+    )
+
+    const toast = screen.getByRole('alert')
+    expect(toast).not.toHaveAttribute('aria-live')
+    expect(toast).toHaveTextContent('Save failed')
+  })
+
+  it('allows callers to override live region urgency', () => {
+    render(
+      <Toast open status="warning" role="alert" aria-live="assertive">
+        Session expiring
+      </Toast>,
+    )
+
+    const toast = screen.getByRole('alert')
+    expect(toast).toHaveAttribute('aria-live', 'assertive')
+    expect(toast).toHaveTextContent('Session expiring')
+  })
+
   it('uses a 3000ms default auto-close duration', () => {
     vi.useFakeTimers()
     const onClose = vi.fn()

packages/ui/src/components/feedback/Toast/Toast.tsx

@@ -1,17 +1,35 @@
 import { forwardRef, type HTMLAttributes, useEffect } from 'react'
 import { cn } from '../../../utils/cn'
 
+type ToastStatus = 'info' | 'success' | 'warning' | 'error'
+type ToastRole = 'status' | 'alert'
+
 export interface ToastProps extends HTMLAttributes<HTMLDivElement> {
   open?: boolean
   duration?: number
   onClose?: () => void
-  status?: 'info' | 'success' | 'warning' | 'error'
+  status?: ToastStatus
+  /** 轻提示的 live region 语义，默认 error 为 alert，其余状态为 status */
+  role?: ToastRole
 }
 
 export const Toast = forwardRef<HTMLDivElement, ToastProps>(function Toast(
-  { className, open = false, duration = 3000, onClose, status = 'info', children, ...props },
+  {
+    className,
+    open = false,
+    duration = 3000,
+    onClose,
+    status = 'info',
+    role,
+    'aria-live': ariaLive,
+    children,
+    ...props
+  },
   ref,
 ) {
+  const toastRole = role ?? (status === 'error' ? 'alert' : 'status')
+  const toastAriaLive = ariaLive ?? (toastRole === 'status' ? 'polite' : undefined)
+
   useEffect(() => {
     if (!open || duration <= 0) {
       return
@@ -29,8 +47,8 @@ export const Toast = forwardRef<HTMLDivElement, ToastProps>(function Toast(
   return (
     <div
       ref={ref}
-      role="status"
-      aria-live="polite"
+      role={toastRole}
+      aria-live={toastAriaLive}
       className={cn(
         'fixed bottom-4 right-4 z-50 min-w-64 rounded-lg border px-4 py-3 text-sm shadow-lg',
         {