Add concept_class and datatype to cascade hierarchy view response

The hierarchy view's ConceptMinimalSerializerRecursive only returned
minimal fields (id, display_name, retired, etc.), forcing clients to
make a second flat+verbose API call to get concept_class and datatype.

Add these two fields to the serializer. This is purely additive —
no existing fields change, the nested entries structure is preserved.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: paynejd

core/concepts/serializers.py

@@ -388,7 +388,8 @@ class ConceptMinimalSerializerRecursive(ConceptAbstractSerializer):
     class Meta:
         model = Concept
         fields = ConceptAbstractSerializer.Meta.fields + (
-            'id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired')
+            'id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired',
+            'concept_class', 'datatype')
 
     def __init__(self, *args, **kwargs):
         if 'mappings' in self.fields:

core/integration_tests/tests_concepts.py

@@ -1768,7 +1768,8 @@ def test_get_200_for_source_version(self):  # pylint: disable=too-many-statement
         entry = response.data['entry']
         self.assertCountEqual(
             list(entry.keys()),
-            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums']
+            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums',
+             'concept_class', 'datatype']
         )
         self.assertEqual(entry['id'], concept1.mnemonic)
         self.assertEqual(entry['type'], 'Concept')
@@ -1826,7 +1827,8 @@ def test_get_200_for_source_version(self):  # pylint: disable=too-many-statement
         entry = response.data['entry']
         self.assertCountEqual(
             list(entry.keys()),
-            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums']
+            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums',
+             'concept_class', 'datatype']
         )
         self.assertEqual(entry['id'], concept2.mnemonic)
         self.assertEqual(entry['type'], 'Concept')
@@ -1868,7 +1870,8 @@ def test_get_200_for_source_version(self):  # pylint: disable=too-many-statement
         entry = response.data['entry']
         self.assertCountEqual(
             list(entry.keys()),
-            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums']
+            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums',
+             'concept_class', 'datatype']
         )
         self.assertEqual(entry['id'], concept1.mnemonic)
         self.assertEqual(entry['type'], 'Concept')
@@ -1883,7 +1886,8 @@ def test_get_200_for_source_version(self):  # pylint: disable=too-many-statement
         entry = response.data['entry']
         self.assertCountEqual(
             list(entry.keys()),
-            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums']
+            ['id', 'type', 'url', 'version_url', 'terminal', 'entries', 'display_name', 'retired', 'checksums',
+             'concept_class', 'datatype']
         )
         self.assertEqual(entry['id'], concept2.mnemonic)
         self.assertEqual(entry['type'], 'Concept')