claude-in-chrome extension fails to connect — 'Browser extension is not connected'

Description

The claude-in-chrome MCP tools cannot connect to the browser extension. Every call to tabs_context_mcp returns "Browser extension is not connected" despite the extension being installed and active in Chrome.

Steps to reproduce

1. Install the Claude browser extension from chrome://extensions
2. Open Chrome with the extension enabled
3. Log into claude.ai
4. Start Claude Code CLI
5. Run /chrome and click "Reconnect extension" — Chrome opens briefly, does something, then closes
6. Attempt to use any mcp__claude-in-chrome__* tool (e.g. tabs_context_mcp)
7. Get error: "Browser extension is not connected"

Expected behavior

The extension should connect and return tab context.

Actual behavior

Connection never establishes. Repeated /chrome reconnect attempts don't resolve it.

Environment

• Claude Code: 2.1.79
• macOS: 26.1 (Build 25B78)
• Platform: darwin (Apple Silicon)
• Shell: zsh

Additional context

• The Claude chat extension works fine for sending prompts in Chrome
• /chrome shows a "Reconnect extension" button which triggers Chrome to open briefly but doesn't fix the issue
• Fully quitting and reopening Chrome did not help
• Restarting Claude Code did not help