Attaches an annotation to an operation definition, returning a new definition.
Combinators never mutate their input — operation definitions are module-level singletons
shared across handler sets, skills, and the registry, so a fresh value keeps the
annotated definition distinct from any other reference to the original.
Type-preserving: an annotation does not change the operation's input/output/service types, so the
returned definition keeps Def (preserving withHandler inference and downstream usage).
Attaches an annotation to an operation definition, returning a new definition. Combinators never mutate their input — operation definitions are module-level singletons shared across handler sets, skills, and the registry, so a fresh value keeps the annotated definition distinct from any other reference to the original.
Type-preserving: an annotation does not change the operation's input/output/service types, so the returned definition keeps
Def(preservingwithHandlerinference and downstream usage).