Function CleanupOld

internal/update/update.go:232–243

CleanupOld removes the execPath+".old" left by a previous Apply. Run at the start of the next launch: on Windows the .old is locked for the prior process's lifetime, so unlink-at-Apply-time fails but unlink-at-next-launch wins. Failure is silent: a leftover .old wastes disk but never breaks the sess

(execPath string)

// fail that update spuriously; a genuinely orphaned partial just waits one
// more launch.
func CleanupOld(execPath string) {
	_ = os.Remove(execPath + ".old")
	matches, err := filepath.Glob(filepath.Join(filepath.Dir(execPath), ".codehamr-update-*"))
	if err != nil {
		return
	}
	for _, m := range matches {
		if info, err := os.Stat(m); err == nil && time.Since(info.ModTime()) > orphanSweepAge {
			_ = os.Remove(m)
		}
	}
}

// orphanSweepAge is how old a .codehamr-update-* temp must be before the
// launch sweep treats it as orphaned rather than another instance's live