fix(byo): name the Node floor the CLI declares

frontend/src/i18n/locales/en.json

@@ -1704,7 +1704,7 @@
       "verified": "{{name}} is listening — mentions will wake it.",
       "stillWaiting": "Still no check-in from {{name}}. Run the command above in Terminal on your computer, and this page will confirm it.",
       "ctaWarning": "{{name}} isn’t listening yet: it won’t answer mentions until the command above is running.",
-      "needs": "Needs Node 18+ with npm and {{tool}} signed in. Run all four lines in one window: the exports last only there.",
+      "needs": "Needs Node 20+ with npm and {{tool}} signed in. Run all four lines in one window: the exports last only there.",
       "osLabel": "Setting up on:",
       "osLinux": "Linux",
       "osMac": "Mac",

frontend/src/i18n/locales/zh-CN.json

@@ -1764,7 +1764,7 @@
       "verified": "{{name}} 已在监听 —— @提及 会唤醒它。",
       "stillWaiting": "{{name}} 还没接入。请在你电脑的终端里运行上面的命令，这里会自动确认。",
       "ctaWarning": "{{name}} 尚未监听：上面的命令运行起来之前，它不会回复 @提及。",
-      "needs": "需要 Node 18+（含 npm）和已登录的 {{tool}}。四行都要在同一个窗口里运行，换了窗口 export 就失效。",
+      "needs": "需要 Node 20+（含 npm）和已登录的 {{tool}}。四行都要在同一个窗口里运行，换了窗口 export 就失效。",
       "osLabel": "你的系统：",
       "osLinux": "Linux",
       "osMac": "Mac",

frontend/src/v2/__tests__/V2AgentBYOListenSnippet.test.tsx

@@ -12,6 +12,10 @@ import { MemoryRouter } from 'react-router-dom';
 import V2AgentBYO from '../components/V2AgentBYO';
 import { AuthContext } from '../../context/AuthContext';
 
+// The page names the Node floor the CLI declares. Read it from cli/package.json
+// rather than copying the number, so a CLI engines bump fails this test.
+const CLI_NODE_FLOOR = Number(require('../../../../cli/package.json').engines.node.match(/\d+/)[0]);
+
 jest.mock('../components/V2NavRail', () => () => null);
 jest.mock('axios', () => {
   const mock = {
@@ -143,11 +147,18 @@ describe('BYO listener snippet', () => {
   test('what it needs is said before the command it is about', async () => {
     await issueToken();
     const needs = screen.getByTestId('byo-listen-needs');
-    expect(needs).toHaveTextContent(/Needs Node 18\+ with npm and Claude Code signed in/);
+    expect(needs).toHaveTextContent(new RegExp(`Needs Node ${CLI_NODE_FLOOR}\\+ with npm and Claude Code signed in`));
     // eslint-disable-next-line no-bitwise
     expect(needs.compareDocumentPosition(listenCommand()) & Node.DOCUMENT_POSITION_FOLLOWING).toBeTruthy();
   });
 
+  // The page renders in English here, so the English test above never reads the
+  // zh-CN copy. Read the zh-CN string straight from the locale file.
+  test('the zh-CN "needs" line names the same Node floor', () => {
+    const zhNeeds: string = require('../../i18n/locales/zh-CN.json').agentByo.listen.needs;
+    expect(zhNeeds).toMatch(new RegExp(`需要 Node ${CLI_NODE_FLOOR}\\+`));
+  });
+
   test('"I use Codex instead" gives a Codex command and says Codex is what it needs', async () => {
     await issueToken();
     fireEvent.click(screen.getByTestId('byo-listen-adapter-switch'));