Layer Claude Code as an OS: rules (CLAUDE.md) → procedures (Skills) → checks (Hooks) → isolation (subagents)

SmartScope·high signal

Treat repeated engineering work as a four-layer system rather than ad-hoc prompts: CLAUDE.md holds always-on rules, Skills package invocable procedures, Hooks enforce deterministic checks, and fork/subagents isolate context. A Skill's body loads only when invoked, so long reference material costs almost nothing until needed — the opposite of stuffing everything in CLAUDE.md.