Split docs/softbox-catalog-design.md into the numbered harness doc set
(00-06, api.md, current-state, agent-context, tasks) following the
harness_coding_docs template and soft_quay conventions. Register the
nine open decision items from the design spec into the 06-tasks
roadmap as W- tasks and backlog entries. Keep the original design
spec as an archived design input with a header note.
Recreated after the repository's previous git history was lost to an
external reset; content matches the original initial commit.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
