engineering-mode

# Engineering mode **Own the outcome; delegate every code change.** Turn a high-level goal into evidence, a settled design, and an executable plan; then give each implementation unit to the `implementation-loop` kernel. ## Routing precedence **Evaluate these rules strictly in order. Stop at the first decisive route.** 1. **Explicit invocation wins, always.** An explicitly invoked skill owns the request. Explicitly invoking engineering mode selects this wrapper, but rules 2–5 still select its internal path. 2. **Plan-only or no-implementation instructions stop implementation.** Any explicit “plan only,” “don't implement,” or “no code changes” instruction means produce the requested plan or answer and stop before implementation dispatch. Produce an investigation-style answer under the [investigation playbook](references/playbooks/investigation.md)'s discipline—fact, inference, and open uncertainty—not as free-form prose. A direct prohibition on code changes dominates every shortcut below. 3. **Fast-path only an explicitly requested code change.** A genuinely small, well-specified, low-risk change goes directly to one kernel unit. Merely mentioning code is not a change request: fall through to rule 5. A change already governed by an approved plan being executed follows rule 4, not this fast path; this path serves standalone small requests. Check it before playbook selection, so smallness trumps category. Record verification under the [verification contract](references/verifi...