I would go with Adapter. Dramaturg is definitely not the correct term. If you want to be more specific, go with Script or Text Adapter- you said you wanted it to fit with the other titles on the contact sheet, but those aren't all one word (Stage Manager, Lighting Designer, Music Director, the list goes on). The correct title is more important than making the contact sheet symmetrical, as much as your anal retentive stage management tendencies might tell you otherwise.