Nursery: Initial integration

StimulusProducer: syncAwaitAllSettlements should pump caller io_context

stimBuffApis/livoxGen1/pcloudStimulusProducer.h

@@ -82,13 +82,9 @@ public:
 		const std::shared_ptr<StimulusBuffer>& buffer) override;
 
 protected:
-	void stimFrameProductionTimesliceInd() override;
-
-	void holdProduceFrameCReq();
-
-	sscl::co::NonViralNonPostingInvoker produceFrameCReq(
-		std::exception_ptr& exceptionPtr,
-		std::function<void()> completion);
+	sscl::co::ViralNonPostingInvoker<void>
+		stimFrameProductionTimesliceCInd(
+			sscl::SyncCancelerForAsyncWork &canceler) override;
 
 public:
 	size_t nDgramsPerStagingBufferFrame;
@@ -112,9 +108,6 @@ public:
 		lightAmbienceStimulusBuffer;
 	std::atomic<std::shared_ptr<PcloudDarkAmbienceStimulusBuffer>>
 		darkAmbienceStimulusBuffer;
-
-	std::optional<sscl::co::NonViralNonPostingInvoker> activeProduceFrameInvoker;
-	std::exception_ptr produceFrameExceptionPtr;
 };
 
 } // namespace stim_buff