coderabbit: add supply chain and malware detection rules

Add security-first review instructions and supply chain attack surface
monitoring based on opendatahub-io/security-config patterns. Includes
named security rules (hardcoded secrets, weak crypto, injection vectors,
privileged containers, sensitive data in logs), path instructions for
IDE/AI agent config injection (Miasma worm defense), diff hiding
(Glassworm defense), dependency manifest tampering, CI/CD workflow
security, and registry config monitoring. Enables settings-dangerous,
hooks-dangerous, mcp-prohibited, and hooks-prohibited tools.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: rna-afk