Error: Failed to spawn Claude Code process: spawn claude ENOENT when using agent mode with Next.js

When following the Next.js setup instructions exactly as documented and trying to use agent mode, I get the following error:
```
Error: Failed to spawn Claude Code process: spawn claude ENOENT
```

**Environment:**
- Framework: Next.js
- Setup: Followed the official Next.js integration guide (added scripts to `app/layout.tsx` with the react-grab and @react-grab/claude-code global scripts)
- Dev command: `npx @react-grab/claude-code@latest && next dev`

**Expected behavior:**
Agent mode should connect to Claude Code CLI and allow elements to be grabbed and sent to the agent with instructions.

**Actual behavior:**
The process fails to spawn with an ENOENT error when attempting to use agent mode.

**Steps to reproduce:**
1. Set up Next.js project with react-grab according to documentation
2. Add the `dev` script: `"dev": "npx @react-grab/claude-code@latest && next dev"`
3. Run `npm run dev`
4. Attempt to use agent mode (grabbing elements) + sending instructions.