Resolve the PasHub PV Connection label to the gov-API credit-gate int 🟥

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

datatypes/epc/domain/tests/test_from_site_notes.py

@@ -122,6 +122,59 @@ class TestPhotovoltaicArrayMapping:
         assert result.sap_energy_source.photovoltaic_arrays is None
 
 
+class TestPvConnectionCoding:
+    """The surveyed "PV Connection" label must resolve to the gov-API int enum
+    the calculator's credit gate keys off (`_pv_connected_to_dwelling_meter`:
+    only int 2 earns the Appendix M credit; int 1 is "present but NOT connected"
+    — zero credit). The raw string fell through the gate's non-int branch to
+    True, crediting PV a dwelling doesn't get to count (issue #1590 bug 3;
+    fixture 499516101839 over-rates by ~6.9 SAP).
+    """
+
+    @pytest.mark.parametrize(
+        "label, expected_code",
+        [
+            ("Not connected to electricity meter", 1),
+            ("Connected to dwellings electricity meter", 2),
+        ],
+    )
+    def test_label_maps_to_gov_api_code(
+        self, label: str, expected_code: int
+    ) -> None:
+        # Arrange
+        data = load("pashub_rdsap_site_notes_example1.json")
+        data["renewables"]["pv_connection"] = label
+        survey = from_dict(PasHubRdSapSiteNotes, data)
+
+        # Act
+        result = EpcPropertyDataMapper.from_site_notes(survey)
+
+        # Assert
+        assert result.sap_energy_source.pv_connection == expected_code
+
+    def test_absent_connection_stays_absent(self) -> None:
+        # Arrange — no PV Connection lodged (fixture default).
+        survey = from_dict(
+            PasHubRdSapSiteNotes, load("pashub_rdsap_site_notes_example1.json")
+        )
+
+        # Act
+        result = EpcPropertyDataMapper.from_site_notes(survey)
+
+        # Assert
+        assert result.sap_energy_source.pv_connection is None
+
+    def test_unknown_label_strict_raises(self) -> None:
+        # Arrange
+        data = load("pashub_rdsap_site_notes_example1.json")
+        data["renewables"]["pv_connection"] = "Some novel connection"
+        survey = from_dict(PasHubRdSapSiteNotes, data)
+
+        # Act / Assert
+        with pytest.raises(UnmappedPasHubLabel, match="PV connection"):
+            EpcPropertyDataMapper.from_site_notes(survey)
+
+
 class TestRoofInsulationNoneCoding:
     """A surveyed roof-space "Insulation At: None" is the assessor explicitly
     recording ZERO loft insulation — `from_site_notes` must lodge an explicit