Claude in Chrome extension never connects (tabs_context_mcp always returns 'not connected')

Bug: Claude in Chrome extension never connects (tabs_context_mcp always returns "Browser extension is not connected")

Environment

• OS: macOS (Darwin 25.5.0)
• Browser: Chrome
• Claude Code: CLI session logged in via icloud.com email
• claude.ai: logged in as "Gee" in Chrome, same account as Claude Code session

Steps taken (in order), all unsuccessful

1. Installed / confirmed "Claude" extension present and enabled at chrome://extensions (single instance, not duplicated).
2. Opened a tab to claude.ai and logged in with the account matching the Claude Code session (confirmed via "Welcome, Gee" screen).
3. Fully quit Chrome (Cmd+Q) and relaunched.
4. Retried the connection after each step above — same error every time.

Expected behavior
Once the extension is installed/enabled and claude.ai is logged in with the matching account, tabs_context_mcp (or any browser automation call) should successfully connect to the browser.

Actual behavior
Every attempt returns:

Browser extension is not connected. Please ensure the Claude browser extension is installed and running (https://claude.ai/chrome), and that you are logged into claude.ai with the same account as Claude Code. If this is your first time connecting to Chrome, you may need to restart Chrome for the installation to take effect.

Additional notes

• chrome://extensions shows a banner "Your browser is managed by your organisation" — however, this is confirmed to be a personal (non-work-managed) Chrome profile, so this banner may be unrelated or itself worth investigating (possibly a leftover/incorrect policy flag).
• Chrome toolbar showed two "Claude" pinned items — appear to be Chrome tab groups (not duplicate extensions) left over from prior sessions, unrelated to the connection issue as far as we could tell.