Update schema to match server responses for SelectionList and TreePath (#11948)

* Annotate default list selection to allow nullable and ensure entry_count is never null

* Add icon (nullable) to TreePath schema

* Bump api version

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,11 +1,15 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 486
+INVENTREE_API_VERSION = 487
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 INVENTREE_API_TEXT = """
 
+v487 -> 2026-05-15 : https://github.com/inventree/InvenTree/pull/11948
+    - Make SelectionList default nullable
+    - Add icon to TreePath schema
+
 v486 -> 2026-05-10 : https://github.com/inventree/InvenTree/pull/11914
     - Adds "maximum_stock" field to the Part model and associated API endpoints
     - Adds "high_stock" filter to the Part API endpoint to filter parts which are above their maximum stock level

src/backend/InvenTree/InvenTree/serializers.py

@@ -315,13 +315,16 @@ class TreePathSerializer(serializers.Serializer):
 
         allowed_fields = ['pk', 'name', *(extra_fields or [])]
 
+        if InvenTree.ready.isGeneratingSchema():
+            return
+
         for field in list(self.fields.keys()):
             if field not in allowed_fields:
                 self.fields.pop(field, None)
 
     pk = serializers.IntegerField(read_only=True)
     name = serializers.CharField(read_only=True)
-    icon = serializers.CharField(required=False, read_only=True)
+    icon = serializers.CharField(required=False, read_only=True, allow_null=True)
 
 
 class InvenTreeMoneySerializer(MoneyField):

src/backend/InvenTree/common/api.py

@@ -1145,6 +1145,10 @@ class SelectionListDetail(RetrieveUpdateDestroyAPI):
     serializer_class = common.serializers.SelectionListSerializer
     permission_classes = [IsAuthenticatedOrReadScope]
 
+    def get_queryset(self):
+        """Override the queryset method to include entry count."""
+        return self.serializer_class.annotate_queryset(super().get_queryset())
+
 
 class EntryMixin:
     """Mixin for SelectionEntry views."""

src/backend/InvenTree/common/serializers.py

@@ -995,7 +995,7 @@ class SelectionListSerializer(InvenTreeModelSerializer):
             'entry_count',
         ]
 
-    default = SelectionEntrySerializer(read_only=True, many=False)
+    default = SelectionEntrySerializer(read_only=True, allow_null=True, many=False)
     choices = SelectionEntrySerializer(source='entries', many=True, required=False)
     entry_count = serializers.IntegerField(read_only=True)