claude update reports 'up to date' but stable endpoint returns outdated version

Bug Description

claude update incorrectly reports "Claude Code is up to date" when a newer version is available.

Steps to Reproduce

1. Have Claude Code 2.1.7 installed (via standalone installer)
2. Run claude update
3. Output says: "Claude Code is up to date (2.1.7)"

Expected Behavior

Should detect and offer to install version 2.1.19 (the actual latest version)

Actual Behavior

Reports 2.1.7 as the latest stable version.

Root Cause

The GCS stable endpoint returns an outdated version:

$ curl -s "https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/stable"
2.1.7

Meanwhile:

• npm shows 2.1.19 as latest: npm view @anthropic-ai/claude-code version
• GitHub releases show v2.1.19 as latest

Workaround

Install via npm instead:

npm install -g @anthropic-ai/claude-code@latest

Environment

• OS: macOS (Darwin 25.2.0)
• Installation method: Standalone installer (curl -fsSL https://claude.ai/install.sh | sh)
• Claude Code version: 2.1.7 (before workaround)