Module registry 

Static registry of built-in readouts.

Returns ReadoutHandle — an Arc<dyn Readout> — so the rest of the engine can hold readouts uniformly whether they’re compile-time builtins (this module) or runtime workload-registered customs (a later push). The Arc allocation per lookup is cheap (one per workload-load + per phase fire, not per render), and the unit-struct readouts have zero-size payloads.

Structs

Registry

Looks up a built-in readout by name. Returns None when the name isn’t registered; callers turn that into a load-time error per feedback_never_ignore_silently.