drop tenure + transaction_type from features (v2.0.0)

Neither field physically affects SAP rating; they're dataset-side metadata
(owner-occupied vs rented, sale vs marketed) and any correlation with
sap_score is confounded with age/condition that the model already sees
through built_form / property_type / construction_age_band.

Dropping reduces feature count and removes a source of spurious split-gain.
MAJOR per ADR-0007 versioning policy (column removal): 1.0.0 -> 2.0.0.

packages/domain/src/domain/ml/tests/test_transform.py

@@ -36,7 +36,7 @@ def test_transform_advertises_version_and_target_columns() -> None:
 
     # Assert
     assert isinstance(schema, TransformSchema)
-    assert schema.transform_version == "1.0.0"
+    assert schema.transform_version == "2.0.0"
     assert schema.transform_version == EpcMlTransform.VERSION
     assert set(schema.target_columns.keys()) == set(_EXPECTED_TARGET_DTYPES.keys())
     for target_name, expected_dtype in _EXPECTED_TARGET_DTYPES.items():
@@ -257,8 +257,6 @@ _NULLABLE_CATEGORICAL_FEATURES: tuple[str, ...] = (
 
 _NON_NULLABLE_CATEGORICAL_FEATURES: tuple[str, ...] = (
     "dwelling_type",
-    "tenure",
-    "transaction_type",
 )
 
 
@@ -289,8 +287,6 @@ def test_to_row_extracts_categorical_features() -> None:
     epc = make_minimal_sap10_epc(
         energy_rating_current=82,
         dwelling_type="End-terrace house",
-        tenure="3",
-        transaction_type="8",
         property_type="0",
         built_form="2",
         region_code="6",
@@ -303,8 +299,8 @@ def test_to_row_extracts_categorical_features() -> None:
 
     # Assert
     assert row["dwelling_type"] == "End-terrace house"
-    assert row["tenure"] == "3"
-    assert row["transaction_type"] == "8"
+    assert "tenure" not in row
+    assert "transaction_type" not in row
     assert row["property_type"] == "0"
     assert row["built_form"] == "2"
     assert row["region_code"] == "6"

packages/domain/src/domain/ml/transform.py

@@ -133,18 +133,6 @@ _FEATURE_COLUMNS: dict[str, ColumnSpec] = {
         categorical=True,
         description="Free-form SAP dwelling-type description, e.g. 'Mid-terrace house'.",
     ),
-    "tenure": ColumnSpec(
-        dtype=str,
-        nullable=False,
-        categorical=True,
-        description="SAP tenure code, stringified int (e.g. '1' owner-occupied).",
-    ),
-    "transaction_type": ColumnSpec(
-        dtype=str,
-        nullable=False,
-        categorical=True,
-        description="SAP transaction type code, stringified int.",
-    ),
     "property_type": ColumnSpec(
         dtype=str,
         nullable=True,
@@ -897,7 +885,7 @@ class EpcMlTransform:
     Version 0.1.0 — schema contract only; feature columns added in subsequent slices.
     """
 
-    VERSION: str = "1.0.0"
+    VERSION: str = "2.0.0"
 
     def schema(self) -> TransformSchema:
         """The cross-repo ML data contract.
@@ -1011,8 +999,6 @@ class EpcMlTransform:
             "percent_draughtproofed": epc.percent_draughtproofed,
             # Features — categoricals (raw strings; cast at parquet write time)
             "dwelling_type": epc.dwelling_type,
-            "tenure": epc.tenure,
-            "transaction_type": epc.transaction_type,
             "property_type": epc.property_type,
             "built_form": epc.built_form,
             "region_code": epc.region_code,