Word for a shadow's owner

In our workflow, we sometimes have someone do duplicate work for someone else, and we call the duplicate work the "shadow" job. This led to a need for a term for the original work in the database, so we started calling the original job the "original shadow", but this is rather awkward, and doesn't really make sense, since something that creates a shadow isn't a shadow, it's the real thing. Is there a word for something that casts a shadow, that pairs nicely with a shadow? For example, if someone sees a "parent" job in the system, they can guess that there will probably be a "child" job as well (unfortunately, we are already using the parent/child analogy for something else). "Caster" works, but it may put you in mind of spells or fishing instead of shadows.

"Child" is to "parent" as "shadow" is to ________.

If you see a _______ job in the system, look for the shadow job that goes with it.

Then Wendy saw that the shadow's ________ was Peter Pan.

Every shadow has a _________.

The Cold War never turned in to World War III; the shadow was worse than the _______.

Within the trade, shadow puppets are called _________.

If you're not in the graphic industry, there's a word you could use that would not cause confusion and is etymologically directly related to your word, and is the exact definition of what you looking for:

Shader

anything or anyone that shades

It fits most of your examples. But it may create confusion if your business is in the computing/graphic industry because of the second definition ( a computer graphics function that produces effects)

Child" is to "parent" as "shadow" is to shader.

If you see a shaderjob in the system, look for the shadow job that goes with it.

Then Wendy saw that the shadow's shader/caster was Peter Pan.

Every shadow has a shader.

I think the word that best fits your needs (and doesn't sound awkward) is source.

According to Merriam-Webster:

Definition of source
1 a : a generative force : cause

Consider incumbent, if refering to the "primary" owner the job (not the job itself).

Definition: The holder of an office or post

Examples: the present incumbent will soon be retiring.

If the incumbent is not performing satisfactorily, the proper action is to correct the situation. If correction is not achieved or there is no improvement, the incumbent should be replaced.