docs: refresh stale science/ migration target in space README

Leandro decided against the existing science/ org; the migration target
is now a new dedicated CAD/Engineering org (name TBD, picked by user,
candidates include HuggingFaceCAD / HuggingEngineering). Mirrors the
<hf-org> placeholder convention used throughout space-setup/.

Co-authored-by: Cursor <cursoragent@cursor.com>

README.md

@@ -16,7 +16,9 @@ textual or visual description of a mechanical part into a valid,
 geometrically correct 3D model?
 
 **Status:** in active development under `michaelr27/AI4Engineering`. Will
-move to `science/cadgenbench-leaderboard` before going public. Reference
-shape inspired by [`adyen/DABstep`](https://huggingface.co/spaces/adyen/DABstep).
+move to a dedicated CAD/Engineering Hub org (name TBD, e.g.
+`HuggingFaceCAD`) as `<hf-org>/cadgenbench-leaderboard` before going
+public. Reference shape inspired by
+[`adyen/DABstep`](https://huggingface.co/spaces/adyen/DABstep).
 
 The previous static-prototype HTML artifacts live in [`legacy/`](legacy/).