fix(ifcdiff): check attributes by default so PredefinedType changes are caught (#8214)

IfcDiff defaulted to relationships=["geometry"], so a plain diff only ever
compared geometry. Attribute-only edits on an element that kept its GlobalId
(a modified or removed PredefinedType, a renamed element, etc.) were silently
missed. The CLI made this worse: --relationships did not list "attributes" or
"geometry" as valid values, so there was no documented way to enable it.

The default is now ["attributes", "geometry"], so a plain `ifcdiff old new`
reports attribute changes alongside geometry changes. The CLI help and the
IfcDiff docstring now document all valid relationship values.

Added a regression test covering a PredefinedType change detected with the
default configuration.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ifcdiff/ifcdiff.py

@@ -51,8 +51,10 @@ class IfcDiff:
 
     :param old: IFC file object for the old model
     :param new: IFC file object for the new model
-    :param relationships: List of relationships to check. None means that only
-        geometry is compared. See RELATIONSHIP_TYPE for available relationships.
+    :param relationships: List of relationships to check. None means that
+        attributes and geometry are compared, so changes such as a modified or
+        removed PredefinedType are reported. See RELATIONSHIP_TYPE for available
+        relationships.
     :param is_shallow: True if you want only the first difference to be listed.
         False if you want all differences to be checked. Choosing False means
         that comparisons will take longer.
@@ -86,7 +88,7 @@ class IfcDiff:
         self.new = new
         self.change_register = {}
         self.representation_ids = {}
-        self.relationships = relationships or ["geometry"]
+        self.relationships = relationships or ["attributes", "geometry"]
         self.precision = 1e-4
         self.is_shallow = is_shallow
         self.filter_elements = filter_elements
@@ -435,7 +437,11 @@ if __name__ == "__main__":
         "-r",
         "--relationships",
         type=str,
-        help='A list of space-separated relationships, chosen from "type", "property", "container", "aggregate", "classification"',
+        help=(
+            'A list of space-separated relationships, chosen from "attributes", "geometry", '
+            '"type", "property", "container", "aggregate", "classification". '
+            'Defaults to "attributes geometry" when omitted.'
+        ),
         default="",
     )
     args = parser.parse_args()

src/ifcdiff/test.py

@@ -77,6 +77,23 @@ class TestIfcDiff:
         assert ifc_diff.deleted_elements == set()
         assert ifc_diff.change_register == {wall.GlobalId: {"attributes_changed": True}}
 
+    def test_changed_predefined_type_is_caught_by_default(self):
+        # Regression test for #8214: a plain diff (no relationships specified)
+        # must report a modified or removed PredefinedType. Previously the
+        # default only compared geometry, so attribute-only edits were missed.
+        ifc_file = setup_project()
+        wall = ifcopenshell.api.root.create_entity(ifc_file, ifc_class="IfcWall", name="Foo")
+        wall.PredefinedType = "SOLIDWALL"
+
+        new_file = ifc_file.from_string(ifc_file.to_string())
+        new_file.by_id(wall.id()).PredefinedType = "NOTDEFINED"
+
+        ifc_diff = ifcdiff.IfcDiff(ifc_file, new_file)
+        ifc_diff.diff()
+        assert ifc_diff.added_elements == set()
+        assert ifc_diff.deleted_elements == set()
+        assert ifc_diff.change_register == {wall.GlobalId: {"attributes_changed": True}}
+
     def test_changed_geometry(self):
         ifc_file = setup_project()
         wall = ifcopenshell.api.root.create_entity(ifc_file, ifc_class="IfcWall", name="Foo")