mapField

named field on a named owner FQN -> its runtime name, or the input unchanged if unmapped. Single-valued where mapMethod needs mapMethodAll beside it: overloads are what split one mojmap name across several runtime ones, and fields do not overload. namedOwnerFqn must DECLARE the field — no row exists under an inheritor and this does not climb, the same constraint Class.getDeclaredField puts on its caller.