Optional override for catalog discovery. Insert this resource
before JackdawPlugin to point the loader at an explicit
catalog.jsn path instead of running the default discovery.
Marker for entities that exist as editor-time visual
indicators. The save filter skips this entity (and its
subtree) so the helper never lands in .jsn; the editor
viewport still renders it.
One enum for every editor parameter value: runtime
OperatorParameters, const operator schemas (Operator::PARAMETERS),
concrete button-call params, and reflected CustomProperties
fields. String uses Cow<'static, str> so the enum can sit in a
const slice.