test(ledger): derive label order follows #2872; binding-ref test imports compute_coverage

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

tests/test_integration_shape_classify.py

@@ -536,7 +536,8 @@ async def test_derive_groups_land_on_rows_and_in_the_summary(seeded):
     order = [g["group"] for g in summary["derive_groups"]]
     assert order[0].startswith("dup:") and order[1] == "name:css:card"
     assert summary["derive_groups"][0]["files"] == 2
-    assert summary["derive_groups"][0]["label"] == ".card"
+    assert summary["derive_groups"][0]["label"] == "slug (identical body)"
+    assert summary["derive_groups"][1]["label"] == ".card"
     assert summary["derive_groups"][0]["size"] == 3
 
     # One of the css copies gets judged → the group shrinks on the next pass.