"Update available" notification shown when already on latest version (Homebrew)

Description

The status line shows an "Update available! Run: brew upgrade claude-code" notification even when already on the latest version.

Steps to reproduce

1. Install Claude Code via Homebrew
2. Update to latest: brew upgrade claude-code
3. Launch claude
4. Status line still shows "Update available" banner

Current version

$ claude --version
2.1.84 (Claude Code)

$ brew info claude-code
==> claude-code: 2.1.84
Installed
/usr/local/Caskroom/claude-code/2.1.84

Both the installed version and the latest Homebrew version are 2.1.84 — the notification should not appear.

Expected behavior

No "Update available" notification when the installed version matches the latest available version.

Environment

• OS: macOS (Darwin 25.3.0)
• Install method: Homebrew cask
• Version: 2.1.84