fix(compare): date report cards with their own inspection date, never the legacy one

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0146VHeLAWjDVE2B5uU67jCB

backend/tests/test_supplementary_enrichment.py

@@ -3,6 +3,7 @@ labels, provider-page URL, graded-vs-carried-forward provenance, and the
 admissions preference/cross-LA detail promoted in the data-foundation PR."""
 
 import types
+from datetime import date
 
 from backend.data_loader import _admissions_row_dict, _ofsted_block
 
@@ -40,6 +41,25 @@ def test_grade_source_graded_vs_carried_forward():
     assert _ofsted_block(_row(), urn=1)["grade_source"] is None
 
 
+def test_ofsted_block_carries_rc_inspection_date():
+    o = _row(
+        ungraded_grade=2,
+        rc_achievement=1,
+        rc_inspection_date=date(2026, 2, 3),
+        inspection_date=date(2021, 10, 7),
+    )
+    block = _ofsted_block(o, urn=138690)
+    assert block["rc_inspection_date"] == "2026-02-03"
+    # The legacy inspection date is still present, unchanged.
+    assert block["inspection_date"] == "2021-10-07"
+
+
+def test_ofsted_block_rc_inspection_date_none_when_absent():
+    o = _row(overall_effectiveness=1, inspection_date=date(2021, 10, 13))
+    block = _ofsted_block(o, urn=136276)
+    assert block["rc_inspection_date"] is None
+
+
 def test_ofsted_block_keeps_existing_keys():
     block = _ofsted_block(_row(overall_effectiveness=2, quality_of_education=2), urn=1)
     for key in ("framework", "inspection_date", "overall_effectiveness",