False positive 'Update available' banner when already on latest version

Description

The status bar (bottom right) persistently shows "Update available! Run: brew upgrade claude-code" even though the installed version is already the latest.

Steps to Reproduce

1. Install claude-code via Homebrew (brew install claude-code)
2. Observe the "Update available" banner in the bottom-right of the Claude Code window
3. Run brew upgrade claude-code — reports already up to date
4. Run brew reinstall claude-code — banner persists after restart

Environment

• Installed version: 2.1.92 (confirmed via claude --version)
• Homebrew cask version: 2.1.92 (confirmed via brew info --json=v2 claude-code)
• brew outdated claude-code: returns nothing (no update available)
• Platform: macOS (Darwin 24.6.0, Apple Silicon)
• Install method: Homebrew cask

Verification

All of the following confirm no update is actually available:

$ claude --version
2.1.92 (Claude Code)

$ brew info claude-code
==> claude-code (Claude Code): 2.1.92
Installed: 2.1.92

$ brew outdated claude-code
(no output)

Expected Behavior

The "Update available" banner should not appear when the installed version matches the latest available version.

Actual Behavior

The banner persists across restarts and even after brew reinstall. There is no local cache file to clear that resolves it. The update check mechanism appears to be out of sync with the actual latest version.