Stabilize the nonblocking choice browser baseline

Why: Wait for the unrelated foreground reply before measuring duplicate replies.

Evidence: All 24 scenarios passed against deployed 8788; independent replay passed the targeted scenario.

Impact: Test synchronization only; the duplicate-reply assertion is unchanged.

Refs: Agent-System-Frontend #89; Agent-System-Dev #565

e2e/work-companion.playwright.ts

@@ -159,6 +159,8 @@ test('keeps optional choices nonblocking and supports defer, reopen, free input
   await page.getByRole('button', { name: '发送', exact: true }).click()
   await expect.poll(() => state.sent?.text).toBe('先聊一下本周的安排')
   expect(state.sent?.taskRef).toBeUndefined()
+  // Receiving the POST is earlier than rendering its legitimate foreground reply.
+  await expect(page.locator('.msg.assistant[data-msg-id="live:run1"]')).toBeVisible()
   const assistantCount = await page.locator('.msg.assistant').count()
   await inline.getByRole('button', { name: '继续选择', exact: true }).click()
   await inline.getByRole('checkbox', { name: '生成摘要', exact: true }).check()