Artinals package

Every upgrade publishes a new package with its own ID. All versions share the original ID (version 1's) 0xffec…b0d4, and the version number counts up, so the highest number is the current code, version 6 here.

A transaction names the exact package ID it calls, so older versions can still be called unless the package itself refuses them, often with a version check on a shared object.

A type keeps the ID of the version that first defined it. Types from version 1 use the original ID for good, while a type added in a later upgrade uses that version's ID.