v1.11.0

Added

• Annotate mode now stamps data-arch-id / data-arch-kind on element primitives.
  data-arch-kind is stamped for every element kind except wall — currently room,
  door, window, opening, furniture, dim, and column (the non-wall members of
  ElementKind; the set is open-ended and grows as kinds are added). Walls are excluded —
  their SVG is unioned geometry stitched across many statements, so per-element attribution
  is ambiguous. Default (non-annotate) output remains byte-identical.
• diffPlans(sourceA, sourceB, opts?): deterministic semantic diff of two plans built on
  describe() — room/opening/furniture changes, per-room bbox edge deltas, circulation deltas,
  and human-readable summary sentences.