Chrome extension MCP server never creates socket (Homebrew install)

Description

The Chrome extension integration fails because the MCP server (claude --claude-in-chrome-mcp) runs but never creates the Unix socket at /tmp/claude-mcp-browser-bridge-{username}.

Environment

• Claude Code version: 2.1.9
• Installation method: Homebrew (/opt/homebrew/Caskroom/claude-code/2.1.9/)
• OS: macOS Darwin 25.1.0
• Chrome extension: Installed and active (debugging mode banner shows "Claude started debugging this browser")

Steps to Reproduce

1. Install Claude Code via Homebrew: brew install --cask claude-code
2. Install Chrome extension from https://claude.ai/chrome
3. Run Claude Code with claude
4. Run /mcp or /plugin to connect to Chrome
5. Attempt to use any mcp__claude-in-chrome__* tool

Expected Behavior

MCP server should create socket at /tmp/claude-mcp-browser-bridge-{username} and Claude Code CLI should connect to it.

Actual Behavior

• /mcp reports "Reconnected to claude-in-chrome"
• MCP server process starts: claude --claude-in-chrome-mcp
• Socket is never created at /tmp/claude-mcp-browser-bridge-*
• All tool calls fail with "Browser extension is not connected"

Debug Logs

2026-01-16T18:34:26.590Z [INFO] [Claude in Chrome] Attempting to connect to: /tmp/claude-mcp-browser-bridge-ahmed
2026-01-16T18:34:26.590Z [INFO] [Claude in Chrome] Socket not found, will be created by server
2026-01-16T18:34:26.592Z [INFO] [Claude in Chrome] Socket error: Error: connect ENOENT /tmp/claude-mcp-browser-bridge-ahmed

The log says "will be created by server" but the socket is never created.

Native Messaging Config

Native messaging host is correctly configured:

{
  "name": "com.anthropic.claude_code_browser_extension",
  "path": "/Users/ahmed/.claude/chrome/chrome-native-host",
  "allowed_origins": ["chrome-extension://fcoeoabgfenejglbffodgkkbkcdhcgfn/"]
}

Wrapper script at ~/.claude/chrome/chrome-native-host:

#!/bin/sh
exec "/opt/homebrew/Caskroom/claude-code/2.1.9/claude" --chrome-native-host

Diagnostic Commands

# Socket never created
ls -la /tmp/claude-mcp-*
# No matches found

# But MCP server IS running
ps aux | grep claude-in-chrome-mcp
# ahmed  7021  /opt/homebrew/Caskroom/claude-code/2.1.9/claude --claude-in-chrome-mcp

Notes

• The docs mention "Chrome integration requires Claude Code installed using the native installer" - this may be intentional, but Homebrew installs should ideally work too
• Multiple MCP server processes can accumulate (had stale 2.1.4 and 2.1.9 running simultaneously)
• Killing and restarting processes does not fix the issue
• Chrome restart does not fix the issue