Previously, articles written by Ersatz Scrivener were represented in
the data model by having a NULL character id. This had several awkward
consequences, such as therebeing no real way to distinguish Ersatz
articles from different players without doubling up on foreign keys
whenever there was a character reference, because there would need to
be a user reference as well.
Using a flag on the article itself is a much cleaner solution. There is
no longer a need to have both character and user FKs. Ersatz-ness is
still a special case, but one easily tracked on articles without
changing how basic objects of the game relate to each other. Ersatz
articles can be treated differently in the stats just as easily while
still being subject to character-specific rules like index assignments.
