Fix: AGENTS.md

A skill file for coding agents (Cursor, Claude Code, Codex). Serve at /AGENTS.md with install, configuration, and usage sections.

# AGENTS.md

## Install
```bash
npm install your-package
```

## Configuration
Set `API_KEY` in the environment.

## Usage
```ts
import { client } from "your-package";
await client.run();
```