fix(web): keep trajectory toolbar Duration/Turns/Calls/Export untranslated

Show the four toolbar terms in English even in the Simplified Chinese
dictionary, including their tooltips, aria labels, and the export failure
message, and update the pinned-zh specs to match.

packages/client/ui-trajectory/tests/toolbar.spec.tsx

@@ -39,7 +39,7 @@ describe('TrajectoryToolbar export', () => {
   it('renders the export button and dispatches the export callback on click', () => {
     const onExport = vi.fn()
     render(<TrajectoryToolbar {...baseProps({ onExport })} />)
-    const button = screen.getByRole('button', { name: '导出会话日志' })
+    const button = screen.getByRole('button', { name: 'Export session log' })
     fireEvent.click(button)
     expect(onExport).toHaveBeenCalledTimes(1)
   })
@@ -47,15 +47,15 @@ describe('TrajectoryToolbar export', () => {
   it('disables the button while an export is in flight and blocks dispatch', () => {
     const onExport = vi.fn()
     render(<TrajectoryToolbar {...baseProps({ exporting: true, onExport })} />)
-    const button = screen.getByRole('button', { name: '导出会话日志' }) as HTMLButtonElement
+    const button = screen.getByRole('button', { name: 'Export session log' }) as HTMLButtonElement
     expect(button.disabled).toBe(true)
     fireEvent.click(button)
     expect(onExport).not.toHaveBeenCalled()
   })
 
   it('surfaces an export failure as the button title', () => {
-    render(<TrajectoryToolbar {...baseProps({ exportError: '导出失败：internal boom' })} />)
-    const button = screen.getByRole('button', { name: '导出会话日志' })
-    expect(button.title).toBe('导出失败：internal boom')
+    render(<TrajectoryToolbar {...baseProps({ exportError: 'Export failed: internal boom' })} />)
+    const button = screen.getByRole('button', { name: 'Export session log' })
+    expect(button.title).toBe('Export failed: internal boom')
   })
 })