The lightest "brainstorm then build". Use when the user wants a quick, cost-aware build that offloads the simpler or mechanical parts to a cheaper model and doesn't need Fable's creative brainstorm — "just design and build it, cheap where it can be". For a straight all-Opus plan→build (no Sonnet offload) use build-ultron; for a Fable-led creative design plus the full ceremony use build-vision. NOT for tiny one-line edits (just do them) or pure design/no-build work.
