**Related issue:** Resolves#21818
# Checklist for submitter
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
## Testing
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* The CLI now detects when SSO is enabled on the server and shows a
warning directing users to authenticate with an API token (with guidance
link) instead of email/password.
* **Bug Fixes**
* Authentication error messaging is now SSO-aware, improving guidance
when credential login fails.
* **Tests**
* Added coverage to verify the authentication guidance changes correctly
based on whether SSO is enabled.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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Co-authored-by: Juan Fernandez <juan@fleetdm.com>
