REQ-EXEC-030 — Anthropic's 4 rules for authoring Claude Code skills

Evaluation of the skill-authoring methodology presented in RD-0005 ("How Anthropic Engineers ACTUALLY Prompt Claude Code", Austin Marchese). Source video transcript: input/transcript.md. Learning deliverables: references/videos/RD-0005/.

Distinct from REQ-EXEC-029 (Karpathy behavioral rules). This evaluates the skill architecture & authoring practices: skills>prompts, the tools layer, composability, invocation flags, and the compounding-loop.