deep-design-3x2

A design-hardening workflow — at least three genuinely different solutions, two independent passes (Opus designs, ChatGPT answers blind then critiques), a re-measure of the claims the pick rests on, one merge, decisions back to the user. Use when the user says "Deep-Design-3x2", "deep design", "do a 3x2 on this", or the old name "3x3" / "Deep-Design-3x3"; when they ask to "harden this design", "get a second opinion on this design" or "get multiple opinions"; or when a design or architecture decision with real cost should get independent passes before they commit to it.