list_connected_browsers returns empty / extension never pairs, despite valid native-host install

Environment: Windows 11, Chrome, Claude Code v2.1.220, Claude in Chrome v1.0.84

Steps to reproduce:

1. Claude Code CLI and Chrome extension both signed into the same personal account (previously mismatched accounts, since fixed via /login)
2. Ran /chrome → Reconnect extension

Observed behavior (progressive across attempts):

• First attempts: opened chrome-extension://.../options.html#options, showing account email and permissions UI, but no connection/pairing action on the page itself
• chrome://extensions → Details for the extension never shows an "Inspect views: service worker" line, even after toggling the extension off/on and after a full reinstall
• After a full restart of both Chrome and the Claude Code process, and reinstalling the extension fresh: Reconnect now opens a window that closes immediately instead of showing the options page
• mcp__claude-in-chrome__list_connected_browsers returns [] at every stage

Already ruled out:

• Duplicate/conflicting extensions (only one instance installed)
• Chrome enterprise/managed policy (chrome://policy shows no policies set)
• Corrupted extension install (fresh reinstall, same result)
• Missing/broken native-messaging registration — confirmed on disk: HKCU\Software\Google\Chrome\NativeMessagingHosts\com.anthropic.claude_code_browser_extension → manifest → chrome-native-host.bat → claude.exe all resolve correctly and

allowed_origins matches the installed extension ID

Expected: Reconnect completes pairing and the browser shows up in list_connected_browsers.