[BUG] CLI sets `minimumVersion` but it isn't honored

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When changing the auto-update channel from latest to stable using the /config command, the user is asked if they want to allow a possible downgrade, or retain the current version until the stable channel catches up. If the user chooses to retain it, a key minimumVersion is added to the user-level settings.json. However, this key isn't honored by the updater. Instead, the version is downgraded anyway. This key isn't in the schema, so I think it doesn't really exist. Probably Claude goofed when adding this feature, and only did it halfway.

Reference: Issue #17770 (where someone else complained that it's undocumented)

What Should Happen?

The minimumVersion settings key should be honored by the updater and Claude Code should never be downgraded automatically to a version older than it specifies.

Error Messages/Logs

$ jq '{autoUpdatesChannel, minimumVersion}' .claude/settings.json
{
  "autoUpdatesChannel": "stable",
  "minimumVersion": "2.1.92"
}

$ claude --version
2.1.92 (Claude Code)

$ claude update
Current version: 2.1.92
Checking for updates to stable version...
Successfully updated from 2.1.92 to version 2.1.85

Steps to Reproduce

1. Upgrade Claude code to the latest version
2. Open Claude Code
3. Run /config
4. Set Auto-update channel to stable
5. Choose Stay on current version (2.1.92) until stable catches up
6. Save and quit
7. Observe the behavior shown here in Error Messages/Logs

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.92

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_