Step anatomy refactor: deprecate Suggested next actions, declare step functions

[dilberryhoundog]

Full proposal: dev/workspace/filebox/steps-preamble-changes.md.

Three moves, taken together:

• Deprecate Suggested next actions. It is a second routing mechanism beside the real one. Conditions carry the routing; the pointer duplicates it in prose, drifts from it, and gives an agent two places to look.
• Weight the step description. The one-line purpose statement stops being a scanning label and becomes the step's self-description to the reading agent.
• Declare the step's function. Below the purpose line, the builder names the step's function from a catalogue — bolded function name, normal text after. Catalogue: error, looping, routing, dormant, handover, support. A step with no declared function is an ordinary working step.

The gain: one routing mechanism instead of two; an agent that reads what a step does rather than inferring it from shared boilerplate; per-step instructions customised in place; a lighter preamble; higher fidelity.

Ripple

Large — this rewrites boilerplate copied verbatim into every DraftHorse document: both templates, steps.md, notation.md, handover.md, condition-writing.md, the build skill, saddler, and every existing skill and agent in extensions/.

Terminology settles here

error drain, error step, problem step and +Handle a Problem are four names for one thing, and error drain sits in the preamble line this refactor rewrites — it is in the universal preamble baked into every document, plus handover.md and saddler's Terms. Choose one set as part of this work rather than touching the same boilerplate twice.

Open questions

• Where does the function catalogue live so a builder can choose from it — the template, a steps.md catalogue, or both?
• One function per step, or several? A handover step that also loops is plausible.
• Retrofit existing documents, or new documents only?
• Does the Step Usage Patterns catalogue in steps.md survive alongside the function list, or does the function list replace it?
• Where do the legitimate uses of Suggested next actions go — the loop instruction, the exit of a finishing step, the bail off unmeetable conditions? Each needs a home before the slot is removed.