Add a first-class DataType.List + ElementDataType companion so object
attributes can store homogeneous scalar lists (e.g. MoveInWorkOrderNumbers,
MoveInPartNumbers) across all four lifecycle paths: script write/read,
static authored default, OPC UA array read, OPC UA array write.
Canonical JSON value codec; whole-list override; element type fixed by base;
idempotent migration widening Value to nvarchar(max) + adding ElementDataType.
Approved via brainstorming.
Joseph Doherty
b238228d8b