Add OpenClaw agent detection check and metadata

[BiosPlus]

Description

OpenClaw is an agentic AI tool that runs persistently and can take autonomous actions on behalf of a user.

The check looks for the following artifacts:

• /Applications/OpenClaw.app bundle
• ~/.openclaw and ~/.openclaw-* profile configuration directories
• LaunchAgent plists (bot.molt.gateway.plist, bot.molt..plist, com.openclaw.)
• Running openclaw processes (including node processes with openclaw in the command line)
• Installed binaries in /usr/local/bin, /opt/homebrew/bin, and user-level npm/bun paths

Checklist

All items must be checked before this PR will be accepted for peer review.
The CI check Verify checklist is complete will fail until every box below is ticked.

• I have created a checks/<check-name>/ directory, with platforms configured in metadata.yaml.
• I have verified that metadata.yaml includes all required fields.
• I have verified that check.sql is a valid osquery query.
• I have permission to share this check publicly.
• I have personally tested this check and verified it produces the expected results.

AI/LLM Disclosure

Did you use any AI/LLM tooling (e.g. ChatGPT, Copilot, Claude) to assist with this contribution? Check all that apply. This is not a disqualifier - it helps apply additional scrutiny to AI-assisted contributions.

• No AI/LLM tooling was used
• Code (SQL, YAML, etc)
• Code comments
• Documentation (README, descriptions, etc.)