docs: refresh stale status strings after org transfer

Space + submissions dataset have moved from michaelr27/... to the
HuggingAI4Engineering org (Phase C of space-setup/migration.md). README
body and app.py ABOUT_MD now reference the current Space slug
(HuggingAI4Engineering/cadgenbench-leaderboard) instead of the
pre-transfer michaelr27/AI4Engineering, and drop the stale
'science/...' migration target that was never used.

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

README.md

@@ -15,10 +15,11 @@ A benchmark for AI-driven CAD generation: how well can a model turn a
 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 a dedicated CAD/Engineering Hub org (name TBD, e.g.
-`HuggingFaceCAD`) as `<hf-org>/cadgenbench-leaderboard` before going
-public. Reference shape inspired by
+**Status:** in active development under
+`HuggingAI4Engineering/cadgenbench-leaderboard` (private; was
+`michaelr27/AI4Engineering` until the org transfer). Will flip to public
+once the eval handler is wired up and the GT dataset is in place.
+Reference shape inspired by
 [`adyen/DABstep`](https://huggingface.co/spaces/adyen/DABstep).
 
 The previous static-prototype HTML artifacts live in [`legacy/`](legacy/).

app.py

@@ -134,8 +134,9 @@ correct 3D model.
 
 ### Status
 
-This Space is in **active development** under `{HF_ORG}/AI4Engineering` and
-will move to `science/cadgenbench-leaderboard` before going public. See
+This Space is in **active development** under
+`{HF_ORG}/cadgenbench-leaderboard` (private). It will flip to public once
+the eval handler is wired up and the GT dataset is in place. See
 `space-setup/` in the source tree for the full build plan.
 """