[BUG] Claude Authentication Failure: Redirect URI mismatch on localhost port

[rengas]

Description:
When attempting to authenticate a Claude subscription within Helix, the OAuth flow fails immediately after the browser opens. The error message indicates that the dynamic localhost port being used by the local callback server is not registered with the OAuth client.

Error Message:
Authorization failed
Redirect URI http://localhost:37907/callback is not supported by client.

Steps to Reproduce:

1. Run the Helix authentication command (e.g., helix auth login or starting the service).
2. Select Claude Subscription as the authentication method.
3. The browser opens to the Anthropic/Claude authorization page.
4. The page immediately displays the "Redirect URI not supported" error.

Environment Details:
Helix Version:2.8.3
OS: Mac
Authentication Method: Claude Pro/Max Subscription

Additional Context:
It appears that Helix is spinning up a callback server on a random/dynamic port (37907), but the Anthropic OAuth application configuration likely expects a fixed port or a specific range.

Suggested Fix/Workaround:
1.Can the callback port be pinned to a specific port (e.g., 3000 or 8080) that is already whitelisted in the Claude OAuth settings?
2. Alternatively, does Helix support a "manual" auth via terminal. I was able to do this once. But It seems the terminal in the broken too blocking me from doing anything