## What changed
- Add `source=codex` to requests sent to the OpenAI developer docs MCP endpoint.
- Preserve OAuth discovery URLs and leave clients for other MCP servers unchanged.
## Testing
- Add unit coverage for regular and streaming HTTP requests, OAuth discovery, and non-docs MCP clients.
GitOrigin-RevId: d04e19fe6fc2db0b5cd7bfb429f0cb821c49b28a