[FEATURE] Make OAuth Callback bind address configurable

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

We run claude code in a dev container. When using MCP servers that authenticate with OAuth, we have to manually curl the callback url from within the container.

We have setup a static port, which we forward to the container, but this hasn't solved the issue, because Claude uses 127.0.0.1 as the bind address. This feels like a gap in the configuration for MCP servers: allowing the port to be set but not the bind address.

Proposed Solution

Provide a configuration option and flag similar to oauth.callbackPort to set the bind address, e.g.:

"oauth": {
  "callbackPort": "9999",
  "callbackAddress": "0.0.0.0"
}

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

MCP server integration

Use Case Example

Using MCP servers when running Claude Code in a container:

1. Run Dev Container with a static MCP callback port forwarded <works>
2. /mcp list to authenticate MCP server <works>
3. Complete OAuth flow in host system browser <works>
4. Upon completion, host browser opens localhost:<port>..... an automatically completes flow <doesn't work>

Additional Context

_No response_