Claude in Chrome MCP connection fails on Windows - extension running but never connects

## Summary
The Claude in Chrome browser extension fails to establish connection with Claude Code via MCP on Windows 11. The
native messaging host starts and creates the named pipe, the extension's service worker runs without errors, but the
connection is never established.

## Environment

• OS: Windows 11 (Build 26200.7628)
• Claude Code: Latest version
• Chrome Extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn

## What Works

• Native messaging host registry key exists and points to correct manifest
• Native host (claude.exe --chrome-native-host) starts and creates pipe \\.\pipe\claude-mcp-browser-bridge-ryanb
• Extension service worker status: ACTIVATED, RUNNING
• Extension DevTools console shows no errors
• MCP logs show "Successfully connected to stdio server" and "Connection established"

## What Doesn't Work

• tabs_context_mcp tool returns "Browser extension is not connected"
• Clicking "Connect Claude Code" button in extension does nothing
• No tabs are created despite tools appearing to execute in logs

## MCP Log Output
{"debug":"Successfully connected to stdio server in 796ms",...}
{"debug":"Connection established with capabilities: {hasTools:true,...}"}
{"debug":"Tool 'tabs_context_mcp' completed successfully in 5s",...}
Tool reports success but nothing actually happens in Chrome.

## Troubleshooting Attempted (4+ hours)

• Uninstalled and reinstalled Chrome extension
• Rebooted Windows
• Restarted Chrome and Claude Code multiple times
• Verified native messaging host manifest
• Verified registry key
• Inspected service worker - confirmed RUNNING, no console errors
• Clicked extension icon and "Connect Claude Code" button repeatedly

chrome-mcp-log.txt