Closes #19924: Record model features on ObjectType (#19939)

* Convert ObjectType to a concrete child model of ContentType

* Add public flag to ObjectType

* Catch post_migrate signal to update ObjectTypes

* Reference ObjectType records instead of registry for feature support

* Automatically create ObjectTypes

* Introduce has_feature() utility function

* ObjectTypeManager should not inherit from ContentTypeManager

* Misc cleanup

* Don't populate ObjectTypes during migration

* Don't automatically create ObjectTypes when a ContentType is created

* Fix test

* Extend has_feature() to accept a model or OT/CT

* Misc cleanup

* Deprecate get_for_id() on ObjectTypeManager

* Rename contenttypes.py to object_types.py

* Add index to features ArrayField

* Keep FK & M2M fields pointing to ContentType

* Add get_for_models() to ObjectTypeManager

* Add tests for manager methods & utility functions

* Fix migrations for M2M relations to ObjectType

* model_is_public() should return False for non-core & non-plugin models

* Order ObjectType by app_label & model name

* Resolve migrations conflict

netbox/core/signals.py

@@ -2,9 +2,9 @@ import logging
 from threading import local
 
 from django.contrib.contenttypes.models import ContentType
-from django.core.exceptions import ValidationError
+from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django.db.models.fields.reverse_related import ManyToManyRel, ManyToOneRel
-from django.db.models.signals import m2m_changed, post_save, pre_delete
+from django.db.models.signals import m2m_changed, post_migrate, post_save, pre_delete
 from django.dispatch import receiver, Signal
 from django.core.signals import request_finished
 from django.utils.translation import gettext_lazy as _
@@ -12,11 +12,12 @@ from django_prometheus.models import model_deletes, model_inserts, model_updates
 
 from core.choices import JobStatusChoices, ObjectChangeActionChoices
 from core.events import *
+from core.models import ObjectType
 from extras.events import enqueue_event
 from extras.utils import run_validators
 from netbox.config import get_config
 from netbox.context import current_request, events_queue
-from netbox.models.features import ChangeLoggingMixin
+from netbox.models.features import ChangeLoggingMixin, get_model_features, model_is_public
 from utilities.exceptions import AbortRequest
 from .models import ConfigRevision, DataSource, ObjectChange
 
@@ -40,6 +41,37 @@ post_sync = Signal()
 clear_events = Signal()
 
 
+#
+# Object types
+#
+
+@receiver(post_migrate)
+def update_object_types(sender, **kwargs):
+    """
+    Create or update the corresponding ObjectType for each model within the migrated app.
+    """
+    for model in sender.get_models():
+        app_label, model_name = model._meta.label_lower.split('.')
+
+        # Determine whether model is public and its supported features
+        is_public = model_is_public(model)
+        features = get_model_features(model)
+
+        # Create/update the ObjectType for the model
+        try:
+            ot = ObjectType.objects.get_by_natural_key(app_label=app_label, model=model_name)
+            ot.public = is_public
+            ot.features = features
+            ot.save()
+        except ObjectDoesNotExist:
+            ObjectType.objects.create(
+                app_label=app_label,
+                model=model_name,
+                public=is_public,
+                features=features,
+            )
+
+
 #
 # Change logging & event handling
 #