docs: add agent skill for Peekaboo CLI

[terryso]

Summary

• Add skills/peekaboo-cli/SKILL.md - Agent skill definition with command reference
• Add skills/peekaboo-cli/references/ - Detailed documentation for 35 commands
• Add docs/agent-skill.md - Installation guide for Claude Code, OpenClaw, and other agents

This skill enables AI agents to use Peekaboo for macOS desktop automation through natural language commands. It's self-contained so users can copy the peekaboo-cli folder to their agent's skills directory without cloning the entire repository.

Installation

# Claude Code
cp -r skills/peekaboo-cli ~/.claude/skills/

# OpenClaw
cp -r skills/peekaboo-cli ~/.openclaw/skills/

Usage

Once installed, agents can perform automation tasks:

• "Take a screenshot of the current window"
• "Click the Submit button"
• "Open Safari and navigate to github.com"

Test plan

• Skill files created with proper structure
• References include all 35 commands
• Installation documentation covers Claude Code and OpenClaw

🤖 Generated with Claude Code