## Issue
Closes#16824
Document that the default GitHub authentication app provided by Coder
requires device flow, and that this behavior cannot be overridden.
## Changes Made
Claude updated the GitHub authentication documentation to:
1. Add a prominent warning in the Default Configuration section
explaining that the default GitHub app requires device flow and ignores
the `CODER_OAUTH2_GITHUB_DEVICE_FLOW` setting
2. Clarify the Device Flow section to indicate that:
- Device flow is always enabled for the default GitHub app
- Device flow is optional for custom GitHub OAuth apps
- The `CODER_OAUTH2_GITHUB_DEVICE_FLOW` setting is ignored when using
the default app
[preview](https://coder.com/docs/@16824-github-device-flow/admin/users/github-auth)
<sub>🤖 Generated with [Claude Code](https://claude.ai/code)</sub>
---------
Co-authored-by: EdwardAngert <17991901+EdwardAngert@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: M Atif Ali <atif@coder.com>
