fix(backend): serve the current Ofsted status from fact_ofsted_latest

The list query and the batch Ofsted fetch each picked 'the latest row' of fact_ofsted_inspection themselves, and _ofsted_block carried an older ungraded grade forward when the latest graded inspection gave none. All three now read marts.fact_ofsted_latest. List rows: ofsted_grade is the grade still in force, ofsted_grade_date when it was awarded or confirmed, ofsted_date the latest visit. The ofsted block gains current_grade and latest_visit and loses grade_source; overall_effectiveness is the graded inspection's own result. A school with only an inspection stays publishable in the sitemap.

Requires fact_ofsted_latest (PR #183's pipeline run) on the database.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/tests/test_ofsted_status_payload.py

@@ -0,0 +1,56 @@
+"""The search badge reads ofsted_grade, ofsted_grade_date and ofsted_date from
+list rows (nextjs-app/lib/utils.ts buildOfstedListBadge). A field the list
+never sends would leave the badge without its year, or worse, fall back to
+"Not yet inspected". The school page reads current_grade and latest_visit from
+the ofsted block (lib/ofstedStatus.ts)."""
+
+import numpy as np
+import pandas as pd
+import pytest
+from fastapi.testclient import TestClient
+
+from backend.schemas import SCHOOL_COLUMNS
+
+
+def test_list_columns_include_the_status_fields():
+    for field in ("ofsted_grade", "ofsted_grade_date", "ofsted_date", "ofsted_rc_date"):
+        assert field in SCHOOL_COLUMNS
+
+
+def _df() -> pd.DataFrame:
+    # Rabbsfarm (102408): latest inspection 17 June 2025 gave no overall grade.
+    return pd.DataFrame([{
+        "urn": 102408, "school_name": "Rabbsfarm Primary School", "phase": "Primary",
+        "school_type": "Community school", "local_authority": "Hillingdon",
+        "address": "Gordon Road, Yiewsley, UB7 8AH", "postcode": "UB7 8AH",
+        "latitude": 51.51, "longitude": -0.47, "year": 202425, "rwm_expected_pct": 58.0,
+        "total_pupils": 60, "gias_total_pupils": 616,
+        "ofsted_grade": np.nan, "ofsted_grade_date": None, "ofsted_date": "2025-06-17",
+        "ofsted_framework": "Schools - S5", "ofsted_rc_date": None,
+    }])
+
+
+@pytest.fixture()
+def client(monkeypatch):
+    from backend import app as app_module
+
+    monkeypatch.setattr(app_module, "load_school_data", _df)
+    monkeypatch.setattr(app_module, "load_latest_school_data", _df)
+    monkeypatch.setattr(app_module, "_place_registry", None)
+    return TestClient(app_module.app, raise_server_exceptions=False)
+
+
+def test_search_rows_carry_the_status_fields(client):
+    resp = client.get("/api/schools")
+    assert resp.status_code == 200, resp.text
+    row = resp.json()["schools"][0]
+    assert row["ofsted_grade"] is None
+    assert row["ofsted_date"] == "2025-06-17"
+    assert "ofsted_grade_date" in row
+
+
+def test_a_school_with_only_an_inspection_is_publishable():
+    from backend.app import _has_publishable_data
+
+    assert _has_publishable_data({"rwm_expected_pct": None, "attainment_8_score": None,
+                                  "ofsted_grade": None, "ofsted_date": "2025-06-17"})