feat(desktop): add open-with menu component for links

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

desktop/src/components/chat/OpenWithMenu.test.tsx

@@ -0,0 +1,17 @@
+import '@testing-library/jest-dom'
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+import { OpenWithMenu } from './OpenWithMenu'
+
+describe('OpenWithMenu', () => {
+  it('offers in-app and system browser choices', () => {
+    const onInApp = vi.fn(); const onSystem = vi.fn()
+    render(<OpenWithMenu url="https://example.com" onOpenInApp={onInApp} onOpenSystem={onSystem} />)
+    fireEvent.click(screen.getByLabelText('打开方式'))
+    fireEvent.click(screen.getByText('应用内浏览器'))
+    expect(onInApp).toHaveBeenCalledWith('https://example.com')
+    fireEvent.click(screen.getByLabelText('打开方式'))
+    fireEvent.click(screen.getByText('系统浏览器'))
+    expect(onSystem).toHaveBeenCalledWith('https://example.com')
+  })
+})

desktop/src/components/chat/OpenWithMenu.tsx

@@ -0,0 +1,21 @@
+import { useState } from 'react'
+import { ChevronDown } from 'lucide-react'
+
+type Props = { url: string; onOpenInApp: (url: string) => void; onOpenSystem: (url: string) => void }
+
+export function OpenWithMenu({ url, onOpenInApp, onOpenSystem }: Props) {
+  const [open, setOpen] = useState(false)
+  return (
+    <span className="relative inline-block">
+      <button aria-label="打开方式" onClick={() => setOpen((v) => !v)} className="inline-flex items-center gap-0.5 text-xs">
+        <ChevronDown size={12} />
+      </button>
+      {open && (
+        <div className="absolute z-10 mt-1 rounded-md border border-[var(--color-border)] bg-[var(--color-surface)] py-1 text-xs shadow">
+          <button className="block w-full px-3 py-1 text-left hover:bg-[var(--color-surface-hover)]" onClick={() => { setOpen(false); onOpenInApp(url) }}>应用内浏览器</button>
+          <button className="block w-full px-3 py-1 text-left hover:bg-[var(--color-surface-hover)]" onClick={() => { setOpen(false); onOpenSystem(url) }}>系统浏览器</button>
+        </div>
+      )}
+    </span>
+  )
+}