Desktop app: "Open in Browser panel" context menu item always opens system default browser instead of the Browser panel

Summary

In the desktop app, right-clicking a URL in a chat message shows a context menu with both "Open in default browser" and "Open in Browser panel". Choosing "Open in Browser panel" always opens the link in the system default browser (Google Chrome here) — identical to "Open in default browser". The in-app Browser panel never receives the URL.

Environment

• Claude desktop app 1.28929.0 (macOS 26.5, arm64), Claude Code 2.1.227
• System default browser: Google Chrome
• Claude in Chrome extension installed and paired (does not appear to be involved — see notes)

Steps to reproduce

1. In a Claude Code session in the desktop app, have the assistant output a message containing a plain URL (in my case a local one: http://127.0.0.1:3245/...).
2. Right-click the link → choose "Open in Browser panel".

Expected

The URL opens in the in-app Browser panel (side panel), as the menu item says.

Actual

The URL opens in the system default browser (Chrome). Reproduced in both states:

• Browser panel closed → opens Chrome.
• Browser panel already open with a live tab (opened by the agent via the Browser MCP preview tools) → still opens Chrome, and the panel's tab list is untouched (verified via the session's tabs_context MCP tool: still exactly one tab, the one the agent opened; the clicked URL never appears).

Notes

• main.log shows no activity at click time: no preview/panel navigation attempt, no error, no fallback message. The click appears to route straight to the OS default-browser open.
• The Claude in Chrome extension bridge is not involved: no claude-in-chrome tool executions (navigate/tabs_create) are logged at click time.
• The agent-driven Browser panel works fine in the same session (preview_start opens and renders pages in the panel), so the panel itself is functional — only the context-menu routing is broken.
• Related but distinct: #81515 asks for links to open in the default browser instead of the panel; this issue is about the existing "Open in Browser panel" menu item not doing what it says.