v0.23.1

Patch release: closes the store-design hole in the Open Questions protocol 0.23.0 shipped. All three plugins (product, architect, scalardb) move to 0.23.1 together.

Changed

• The Open Questions store is one file, and the architect deliverable is a view of it. The
  protocol named two stores — work/context.md § Open Questions and
  reports/00_requirements/open-questions.md — without saying which was authoritative or how IDs
  were allocated. Two consequences, both reachable in a normal handoff run: product and architect
  could mint the same OQ-004 for different questions, since neither had a rule saying where the
  next ID comes from; and an answer recorded on one side never reached the other, so a question
  architect resolved stayed unasked for a later product rerun. work/context.md is now the
  store for the whole project, reports/00_requirements/open-questions.md is rendered from it as
  a deliverable rather than kept as a second source, and a new ID is max(OQ-###) + 1 over the
  store. This is the same rule work/traceability.json already followed — never start a second
  file — applied to the question that crosses the boundary in both directions.