Claude in Chrome never connects to Claude Code CLI — list_connected_browsers returns [] / "Browser extension is not connected" despite matching account and full Chrome restart

The Claude Code CLI cannot connect to the Claude in Chrome extension. Every browser tool fails because no browser is ever paired: list_connected_browsers returns an empty array [], and any browser action returns "Browser extension is not connected." This persists across full Chrome restarts, a Claude Code re-login, and confirming both sides are on the same claude.ai account.

Environment:

• OS: macOS 26.5.2 (build 25F84)
• Claude Code: 2.1.206
• Google Chrome: 149.0.7827.201
• Claude in Chrome extension: installed, running, and logged in (extension Settings shows the account signed in, microphone access granted, notifications enabled)
• Auth: Claude Code is authenticated via claude.ai account login (subscription), NOT an API key — both ANTHROPIC_API_KEY and ANTHROPIC_AUTH_TOKEN are unset in the environment
• Account: the same claude.ai account is signed in to both the extension and the Claude Code CLI

Expected behavior:
list_connected_browsers returns the running Chrome instance, and tabs_context_mcp can create/attach to a tab so browser automation works.

Actual behavior:
The extension never pairs with the CLI session:

• list_connected_browsers →

[]

• tabs_context_mcp (with createIfEmpty: true) →

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.

Troubleshooting already tried (all failed):

1. Confirmed the extension is installed, running, and logged in via its Settings page.
2. Confirmed Claude Code uses an account login, not an API key (ANTHROPIC_API_KEY / ANTHROPIC_AUTH_TOKEN both unset).
3. Re-ran /login in Claude Code (reported "Login successful").
4. Fully quit Chrome with ⌘Q (not just closing the window) and reopened — multiple times, including after the re-login.
5. Confirmed the MCP browser tools load correctly on the Claude Code side (via ToolSearch); the failure is purely the extension↔CLI handshake, not tool availability.
6. The extension UI exposes no "Connect" / device-pairing button, and shows "No sites have been approved yet."

Note:

• No corporate proxy or custom network setup.
• Happy to provide extension logs or any other diagnostics — please point me at where the extension connection logs live.