fix(stealth): 修复 headed 模式下 stealth 失效并统一策略

- 修复 launch 协议未透传 stealth 导致 --headed 下补丁失效的问题\n- 在 BrowserManager 引入 StealthPolicy，统一 local/CDP/provider 能力决策\n- 增加 launch 返回 stealth 状态并在 --debug 输出连接类型与能力\n- 补充 local/CDP 回归测试与 bot.sannysoft.com 自动检查脚本\n- 同步 README、CLI help、技能文档与 CDP 文档中的 stealth 能力矩阵

src/stealth.test.ts

@@ -0,0 +1,54 @@
+import { afterEach, describe, expect, it } from 'vitest';
+import { BrowserManager } from './browser.js';
+
+async function readWebdriverSignals(browser: BrowserManager): Promise<{
+  value: boolean | undefined;
+  inNavigator: boolean;
+  ownNavigator: boolean;
+  ownPrototype: boolean;
+}> {
+  const page = browser.getPage();
+  await page.goto('about:blank');
+  return page.evaluate(() => {
+    const prototype = Object.getPrototypeOf(navigator);
+    return {
+      value: navigator.webdriver,
+      inNavigator: 'webdriver' in navigator,
+      ownNavigator: Object.prototype.hasOwnProperty.call(navigator, 'webdriver'),
+      ownPrototype: Object.prototype.hasOwnProperty.call(prototype, 'webdriver'),
+    };
+  });
+}
+
+describe('Stealth mode', () => {
+  let browser: BrowserManager;
+
+  afterEach(async () => {
+    if (browser?.isLaunched()) {
+      await browser.close();
+    }
+  });
+
+  it('removes navigator.webdriver when stealth is enabled', async () => {
+    browser = new BrowserManager();
+    await browser.launch({ headless: true, stealth: true });
+
+    const signals = await readWebdriverSignals(browser);
+    expect(signals.value).toBeUndefined();
+    expect(signals.inNavigator).toBe(false);
+    expect(signals.ownNavigator).toBe(false);
+    expect(signals.ownPrototype).toBe(false);
+  });
+
+  it('applies stealth patches to contexts created by newWindow', async () => {
+    browser = new BrowserManager();
+    await browser.launch({ headless: true, stealth: true });
+    await browser.newWindow();
+
+    const signals = await readWebdriverSignals(browser);
+    expect(signals.value).toBeUndefined();
+    expect(signals.inNavigator).toBe(false);
+    expect(signals.ownNavigator).toBe(false);
+    expect(signals.ownPrototype).toBe(false);
+  });
+});