[BUG] Claude in Chrome: Native messaging bridge socket never created on Linux — extension side panel works but CLI cannot connect (ENOENT)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

## Environment

• OS: Ubuntu Linux (6.11.0-29-generic)
• Claude Code: v2.1.37
• Chrome: latest (just updated)
• Extension: installed from Chrome Web Store

## Problem
Claude in Chrome extension side panel works (can chat with Claude),
but the native messaging bridge to Claude Code CLI never establishes.

## Details

• Native messaging host manifest correctly placed in ~/.config/google-chrome/NativeMessagingHosts/
• Native host script works when invoked manually (creates socket at /tmp/claude-mcp-browser-bridge-{user}/{PID}.sock)
• Chrome extension never invokes the native host — no socket file is created
• CLI debug log shows: Socket error (code: ENOENT): connect ENOENT /tmp/claude-mcp-browser-bridge-{user}
• Extension service worker console shows no errors
• Same account used on both CLI and extension

What Should Happen?

## Expected
Native messaging bridge socket should be created, enabling CLI browser automation.

Error Messages/Logs

Steps to Reproduce

1. Install Claude in Chrome extension on Linux
2. Run claude --chrome
3. Extension side panel opens and works
4. ls /tmp/claude-mcp-browser-bridge-* shows nothing
5. All browser automation tools return "Browser extension is not connected"

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.37

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

PowerShell

Additional Information

_No response_