claude doctor always shows 'Auto-update channel: latest' ignoring autoUpdatesChannel config

Description

claude doctor always displays Auto-update channel: latest regardless of the autoUpdatesChannel value set in ~/.claude.json.

Steps to reproduce

1. Set "autoUpdatesChannel": "stable" in ~/.claude.json
2. Run claude doctor
3. Output still shows Auto-update channel: latest

Expected behavior

claude doctor should read and display the configured autoUpdatesChannel value from ~/.claude.json.

Actual behavior

Always displays latest regardless of config.

Config file (~/.claude.json)

{
  "autoUpdates": true,
  "autoUpdatesChannel": "stable",
  ...
}

Environment

• Claude Code version: 2.1.72 (native)
• OS: Ubuntu 24.04.3 LTS
• Install method: native

Additional context

• The field name autoUpdatesChannel was confirmed correct via the schema at claude-code-settings.schema.json
• Also confirmed the field name exists in the binary via strings search
• claude config set autoUpdateChannel stable (via CLI) did not persist the value either — it silently succeeded but didn't write to the config file