Auto-updater downgrades to older version (2.1.19 → 2.1.7)

Bug Description

The claude update command incorrectly "updates" from version 2.1.19 to version 2.1.7, which is actually a downgrade.

Steps to Reproduce

1. Have Claude Code version 2.1.19 installed
2. Run claude update
3. Observe output:

``
Current version: 2.1.19
Checking for updates to stable version...
Successfully updated from 2.1.19 to version 2.1.7
``

Expected Behavior

The updater should recognize that 2.1.19 > 2.1.7 and either:

• Report "Already on latest version" if 2.1.19 is the latest
• Update to a version newer than 2.1.19 if one exists

Actual Behavior

The updater downgrades from 2.1.19 to 2.1.7.

Root Cause Hypothesis

The version comparison logic may be comparing version components as strings rather than integers, causing "19" to be compared lexicographically as less than "7" (since "1" < "7").

Environment

• OS: macOS (Darwin 24.6.0)
• Previous version: 2.1.19
• "Updated" version: 2.1.7