fix(desktop): keep the settings permission menu inside the window

The default-permission menu in Settings > General grew rightwards from the
trigger's left edge. The trigger sits at the end of the row, so the 340px
menu ran past the content column and was clipped. Add a menuAlign option
and right-align the menu there; composer callers keep the left alignment.

Fixes #1474

desktop/src/components/controls/PermissionModeSelector.test.tsx

@@ -479,6 +479,26 @@ describe('PermissionModeSelector', () => {
     expect(onChange).toHaveBeenCalledWith('acceptEdits')
   })
 
+  it('opens the desktop menu from the trigger start edge by default', () => {
+    render(<PermissionModeSelector value="default" onChange={vi.fn()} />)
+
+    fireEvent.click(screen.getByRole('button', { name: 'Ask permissions' }))
+
+    const menu = screen.getByRole('menu')
+    expect(menu).toHaveClass('left-0')
+    expect(menu).not.toHaveClass('right-0')
+  })
+
+  it('anchors the desktop menu to the trigger end edge when asked to align right', () => {
+    render(<PermissionModeSelector value="default" onChange={vi.fn()} menuAlign="right" />)
+
+    fireEvent.click(screen.getByRole('button', { name: 'Ask permissions' }))
+
+    const menu = screen.getByRole('menu')
+    expect(menu).toHaveClass('right-0')
+    expect(menu).not.toHaveClass('left-0')
+  })
+
   it('shows Auto beside the existing permission modes', () => {
     render(<PermissionModeSelector value="default" onChange={vi.fn()} />)
 

desktop/src/components/controls/PermissionModeSelector.tsx

@@ -73,6 +73,11 @@ type Props = {
    */
   trigger?: 'chip' | 'elevatedOnly'
   menuPlacement?: 'top' | 'bottom'
+  /**
+   * Which trigger edge the desktop menu lines up with. `right` keeps it inside
+   * the container when the trigger sits at the end of a row, as in Settings.
+   */
+  menuAlign?: 'left' | 'right'
   /** Controlled mode: override current value */
   value?: PermissionMode
   /** Controlled mode: called on change instead of updating global store */
@@ -80,7 +85,7 @@ type Props = {
 }
 
 export const PermissionModeSelector = forwardRef<PermissionModeSelectorHandle, Props>(function PermissionModeSelector(
-  { sessionId, workDir: workDirProp, compact = false, trigger = 'chip', menuPlacement = 'top', value, onChange }: Props = {},
+  { sessionId, workDir: workDirProp, compact = false, trigger = 'chip', menuPlacement = 'top', menuAlign = 'left', value, onChange }: Props = {},
   handleRef,
 ) {
   const t = useTranslation()
@@ -175,6 +180,7 @@ export const PermissionModeSelector = forwardRef<PermissionModeSelectorHandle, P
   const menuPlacementClass = menuPlacement === 'bottom'
     ? 'top-full mt-2'
     : 'bottom-full mb-2'
+  const menuAlignClass = menuAlign === 'right' ? 'right-0' : 'left-0'
   // Generated, not hard-coded: the previous literal id was rendered by both the
   // sheet branch and the desktop branch, so `aria-controls` pointed at whichever
   // duplicate the browser resolved first.
@@ -350,7 +356,7 @@ export const PermissionModeSelector = forwardRef<PermissionModeSelectorHandle, P
             </div>
           </MobileBottomSheet>
         ) : (
-          <div id={menuId} ref={menuRef} role="menu" className={`absolute left-0 ${menuPlacementClass} z-[var(--z-dropdown)] w-[340px] ${COMPOSER_POPOVER}`}>
+          <div id={menuId} ref={menuRef} role="menu" className={`absolute ${menuAlignClass} ${menuPlacementClass} z-[var(--z-dropdown)] w-[340px] ${COMPOSER_POPOVER}`}>
             <div className={COMPOSER_MENU_SECTION}>
               {t('permMode.executionPermissions')}
             </div>

desktop/src/pages/settings/GeneralSettings.tsx

@@ -952,6 +952,7 @@ export function GeneralSettings() {
               onChange={(mode) => void setPermissionMode(mode)}
               workDir={t('settings.general.defaultPermissionScope')}
               menuPlacement="bottom"
+              menuAlign="right"
             />
           </SettingsRow>
           <SettingsRow

desktop/src/pages/settings/GeneralSettingsPermissionMenu.test.tsx

@@ -0,0 +1,38 @@
+import { cleanup, fireEvent, render, screen, within } from '@testing-library/react'
+import '@testing-library/jest-dom'
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { useOpenTargetStore } from '@/stores/openTargetStore'
+import { useSettingsStore } from '@/stores/settingsStore'
+import { GeneralSettings } from './GeneralSettings'
+
+describe('General settings default permission menu', () => {
+  beforeEach(() => {
+    useSettingsStore.setState({
+      locale: 'zh',
+      permissionMode: 'default',
+      fetchOutputStyles: async () => {},
+      fetchAppMode: async () => {},
+    })
+    useOpenTargetStore.setState({ ensureTargets: async () => {} })
+  })
+
+  afterEach(() => {
+    cleanup()
+    useSettingsStore.setState(useSettingsStore.getInitialState(), true)
+    useOpenTargetStore.setState(useOpenTargetStore.getInitialState(), true)
+  })
+
+  // The trigger sits at the end of a settings row, against the right edge of
+  // the scrolling content column. A menu growing rightwards from the trigger's
+  // left edge ran past the window and was clipped (#1474).
+  it('opens the menu leftwards from the trigger at the end of the row', () => {
+    render(<GeneralSettings />)
+
+    fireEvent.click(screen.getByRole('button', { name: '询问权限' }))
+
+    const menu = screen.getByRole('menu')
+    expect(within(menu).getByRole('menuitem', { name: /询问权限/ })).toBeInTheDocument()
+    expect(menu).toHaveClass('right-0')
+    expect(menu).not.toHaveClass('left-0')
+  })
+})