Application-owned definition of a memory Lens.
A Lens combines a unique name, a Gralkor.Ontology, a storage scope, and a
module implementing Gralkor.Lens.Ingestion. :operator scope isolates
storage by operator and Lens name. :global scope writes to the shared
global pool while retaining the Lens name as provenance.
Consumers normally register Lens definitions in :jido_gralkor, :lenses
and resolve them through Gralkor.Client, rather than constructing this
struct directly.