feat(workout): hide registry conversion from golden path

Let the Workout generated interaction builder satisfy DispatchRegistry directly and guard canonical sources/docs against .into_registry() so the beginner path does not teach manual registry conversion.

req: examples/001

req: examples/006

req: public_api/002

examples/workout/src/lib.rs

@@ -724,7 +724,6 @@ pub fn interactions(state: AppState) -> impl hemx_axum::DispatchRegistry {
             ui::workout::record_native_haptic_ack,
             record_native_haptic_ack,
         )
-        .into_registry()
 }
 
 fn effects(state: &WorkoutState, status: impl Into<String>) -> impl IntoEffect {