New test suite covering:
- HDOC: anti-heredoc instruction present in all 9 file-writing agents
- SKILL: skills: frontmatter present in all 11 agents
- HOOK: commented hooks pattern in file-writing agents
- SPAWN: no stale workaround patterns, valid agent type references
- AGENT: required frontmatter fields (name, description, tools, color)
509 total tests (462 existing + 47 new), 0 failures.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>