C1 put everything in one always-on file. That works, but every convention costs context on every turn, and a CLAUDE.md "never do X" line is only a suggestion — Claude can still do X. In C2 you make steering scoped (rules that load only when relevant), reusable (a skill that triggers by description, a subagent that runs on a cheaper model), and enforced (a hook that blocks destructive commands). Claude Code itself helps you build the kit — and then uses it.
