feat(stealth): 优化隐身对抗并引入双版本发布体系

- 将 CreepJS like headless 指标优化到 0%（headless/stealth 维持 0%）

- 新增 ActiveText 与 prefers-color-scheme 探针修复

- 版本号采用 <upstream>-fork.<fork> 格式并在 --version 输出 upstream/fork

- 更新 README、SKILL 与 docs 中的版本体系说明

src/browser.ts

@@ -1542,7 +1542,7 @@ export class BrowserManager {
       // Expand ~ to home directory since it won't be shell-expanded
       const profilePath = options.profile!.replace(/^~\//, os.homedir() + '/');
       context = await launcher.launchPersistentContext(profilePath, {
-        headless: options.headless ?? true,
+        headless: options.headless ?? false,
         executablePath: options.executablePath,
         args: baseArgs,
         viewport,
@@ -1558,7 +1558,7 @@ export class BrowserManager {
     } else {
       // Regular ephemeral browser
       this.browser = await launcher.launch({
-        headless: options.headless ?? true,
+        headless: options.headless ?? false,
         executablePath: options.executablePath,
         args: baseArgs,
       });