A WireGraphMapVariant value. key/value pick the nested KeyWrapper_<K>
/ Map_<K>_<V> members; entries are the concrete pairs (empty = an empty
map, the at-rest state of a fresh MapVar brick).
A wire graph array variant value, mirroring the engine’s
WireGraphArrayVariant union (one array member per element type). Each
member is a WireGraph*Array struct holding a single Values array.
A wire graph variant value. The members mirror the engine’s
WireGraphVariant union (f64, i64, bool, weak_object,
WireGraphExec, Vector, Rotator, Quat, str, LinearColor);
WireGraphPrimMathVariant uses the numeric/spatial subset.
A tagged-union/variant: a name and the ordered list of member type names it
can hold. The encoded value is a uint tag (the member index) followed by the
value of that member type. Newer schemas use these for wire graph variants
(e.g. WireGraphVariant, WireGraphPrimMathVariant, WireGraphArrayVariant).