validate totalSleepMS does not have a negative value

When the IPC call takes longer than sleepIntervalMS on an overloaded CI
runner), sleepIntervalMS - dur.count() produces a negative result that
wraps to a huge size_t value, causing the worker to sleep for an
effectively infinite duration. After that, no more signals are ever
polled — any test waiting for a signal hits the 30-second timeout.

Author: sandboxcoder

obs-studio-client/source/nodeobs_service.cpp

@@ -348,7 +348,8 @@ void service::worker()
 
 		auto tp_end = std::chrono::high_resolution_clock::now();
 		auto dur = std::chrono::duration_cast<std::chrono::milliseconds>(tp_end - tp_start);
-		totalSleepMS = sleepIntervalMS - dur.count();
+		auto durCount = dur.count();
+		totalSleepMS = durCount < sleepIntervalMS ? sleepIntervalMS - durCount : 0;
 		std::this_thread::sleep_for(std::chrono::milliseconds(totalSleepMS));
 	}
 

obs-studio-client/source/worker-signals.hpp

@@ -132,7 +132,8 @@ class WorkerSignals {
 
 			auto tp_end = std::chrono::high_resolution_clock::now();
 			auto dur = std::chrono::duration_cast<std::chrono::milliseconds>(tp_end - tp_start);
-			totalSleepMS = sleepIntervalMS - dur.count();
+			auto durCount = dur.count();
+			totalSleepMS = durCount < sleepIntervalMS ? sleepIntervalMS - durCount : 0;
 			std::this_thread::sleep_for(std::chrono::milliseconds(totalSleepMS));
 		}