[Feature Request] Allow custom domain allowlist in Claude Preview MCP

Bug Description
Feature Request: Allow custom domain allowlist in Claude Preview

Problem:
The Preview feature currently blocks all non-localhost URLs with the error: "link to auth.treasurypath.test was blocked. preview only supports localhost urls". However, many local development setups use custom domains (e.g. app.myproject.local) mapped to 127.0.0.1 via /etc/hosts or local DNS. These are still local services running on the developer's machine, but Preview treats them as external URLs and blocks navigation/API calls to them.

Impact:
This makes Preview mode unusable for projects that rely on custom local domains

Environment Info

• Platform: darwin
• Terminal: WarpTerminal
• Version: 2.1.50
• Feedback ID: 0ba63ac7-cfe9-4315-89a0-f1e09c761e2b