Return a lazy constant for the given factory, either globally or per-signal.
A function, or class constructor producing a value that will be cached by
$``() as a permanent-per-signal constant at a given call site.
A configurable access point for a lazily-created service.
A function, or class constructor producing a value that will be cached by a
service() accessor for the life of the root job. (Or until overridden via
a service accessor's set/unset methods.)
Tools for sharing tasks, values, services, etc., especially across job boundaries, but also across reactive expression lifetimes (similar to React hooks).