test(ledger): derive group sizes follow the #2872 order

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_integration_shape_classify.py

@@ -538,7 +538,7 @@ async def test_derive_groups_land_on_rows_and_in_the_summary(seeded):
     assert summary["derive_groups"][0]["files"] == 2
     assert summary["derive_groups"][0]["label"] == "slug (identical body)"
     assert summary["derive_groups"][1]["label"] == ".card"
-    assert summary["derive_groups"][0]["size"] == 3
+    assert summary["derive_groups"][0]["size"] == 2 and summary["derive_groups"][1]["size"] == 3
 
     # One of the css copies gets judged → the group shrinks on the next pass.
     await classify_shapes(owner, pid, [