ValueError when CRUD event involves AnonymousUser

[sgordon16]

ValueError when CRUD event involves AnonymousUser: Field 'id' expected a number but got ''

Describe the bug

A ValueError occurs when a CRUD event is performed by an AnonymousUser. Instead of returning None for the user field, an empty string ('') is being passed.

Error Details

*** ValueError: Field 'id' expected a number but got ''.
Traceback (most recent call last):
  File "/app/.venv/lib/python3.11/site-packages/django/db/models/fields/related_descriptors.py", line 218, in __get__
    rel_obj = self.field.get_cached_value(instance)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib/python3.11/site-packages/django/db/models/fields/mixins.py", line 15, in get_cached_value
    return instance._state.fields_cache[cache_name]
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
KeyError: 'user'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/app/.venv/lib/python3.11/site-packages/django/db/models/fields/__init__.py", line 2053, in get_prep_value
    return int(value)
           ^^^^^^^^^^
ValueError: invalid literal for int() with base 10: ''

Cause

The user field is a nullable primary key field that expects either an integer or None. When the user is anonymous, the field should be set to None, but it is receiving an empty string instead.

Expected behavior

The user field should return None for an AnonymousUser, not an empty string.