Oh right, yeah, we like to do things gracefully around here when
there's no corresponding color/species record yet!
Paying more attention to this, I'm thinking like… it could be a cool
idea to, in modeling, *create* the new color/species record, and just
not have all the attributes filled in yet? Especially now that we're
less dependent on attributes like `standard` to be set for correct
functioning.
But for now, we follow the same strategy we do elsewhere in the app: a
pet type can have `color_id` and `species_id` that don't correspond to
a real record, and we cover over that smoothly.
