Doctor command shows unknown install method for @anthropic-ai/claude-code

Bug Report

Description:
The claude doctor command shows Config install method: unknown when Claude Code is installed via git clone + npm install -g @anthropic-ai/claude-code.

Installation Method:

• Git clone of repository
• npm install -g @anthropic-ai/claude-code
• Version: 1.0.56

Expected Behavior:
Doctor should detect and report the install method as 'npm' or 'git+npm'

Actual Behavior:
Config install method: unknown

Environment:

• OS: Windows
• Node.js: v22.17.0
• npm: 10.9.2

Impact:
Functionality works correctly, but install method detection affects troubleshooting capabilities.

Reproduction Steps:

1. Clone Claude Code repository
2. Run npm install -g @anthropic-ai/claude-code
3. Run claude doctor
4. Observe "Config install method: unknown" in output

Expected Fix:
Update doctor command's detection logic to recognize the @anthropic-ai/claude-code package name and git+npm installation method.