Update notification ignores autoUpdatesChannel setting

Description

When autoUpdatesChannel is set to "stable" in ~/.claude/settings.json, the "Update available! Run: brew upgrade claude-code" notification still appears even when the user is already on the latest stable release.

Running brew upgrade claude-code returns "nothing to upgrade" because there is no newer stable version — the available update is presumably on a pre-release/beta channel.

Expected behavior

The update notification should respect the autoUpdatesChannel setting. If the user is on "stable" and already running the latest stable release, no update notification should be shown — even if a newer pre-release version exists.

Current behavior

The notification appears regardless of the configured channel, prompting the user to run an upgrade that has nothing to install.

Environment

• Claude Code version: 2.1.92
• Install method: Homebrew (cask)
• OS: macOS (Darwin 25.4.0)
• Settings:

``json
{
"autoUpdatesChannel": "stable"
}
``

Notes

The user likes having update notifications — they just want them to be valid. The current workaround is DISABLE_AUTOUPDATER=1, but that's a sledgehammer when the real fix is making the notification channel-aware.