Publish the anti-machinery skill

[CodingCossack]

What changed

• publishes the current local anti-machinery skill and OpenAI interface metadata
• adds concise installation, purpose, relationship, and contribution documentation
• adds an MIT licence and private security-reporting path
• adds one small structural validator and pinned validation workflow

Why

anti-machinery is a distinct skill with its own activation boundary, public identity, installation path, and release lifecycle. It remains compatible with change-with-proof without becoming its hard dependency.

Validation

• ./scripts/validate.sh
• official skill-creator quick_validate.py
• local payload matches /Users/dmytro/.codex/skills/anti-machinery
• npx -y skills add ./work/anti-machinery --list discovered exactly anti-machinery