False update notification when already on latest version

Question

## Description

Claude Code shows an update notification, but when running `brew upgrade claude-code`, Homebrew reports that the latest version is already installed:

```
$ brew upgrade claude-code
Warning: Not upgrading claude-code, the latest version is already installed
```

## Expected Behavior

No update notification should appear when the latest version is already installed.

## Actual Behavior

An update notification is shown even though no update is available.

## Environment

- Platform