Auto-cleanup old versions after update

[hotovson]

The
standalone installer keeps old binaries in ~/.local/share/claude/versions/ without ever cleaning them up.
Each version is ~175MB, so after a few updates it wastes 500MB+. The updater should delete old versions after
successfully symlinking the new one.

[github-actions]

Found 1 possible duplicate issue:

1. [Feature Request] Implement automatic cleanup of old Claude versions during updates #14980

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[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.