fix(app): the log written to the end of the closing, each step of it with its time; the Discord thread idle outside the driver mode

The log service stopped with applicationQuitOrder, so whatever was logged while the simulator closed was lost; it now runs until StopLogService() and writes out what came before. The closing logs each of its steps with the time since it began, to tell where a closing that hangs stops. Outside the driver mode the Discord thread spun a core in its loop, it now sleeps a second between the checks.

nodebank_previews_standalone.cpp

@@ -290,9 +290,9 @@ int generate_nodebank_previews(int Argc, char *Argv[])
 	std::thread logservice(LogService);
 
 	auto const finish = [&](int const Result) {
-		// give the log service time to write out what's left
-		std::this_thread::sleep_for(std::chrono::milliseconds(200));
+		// the log service writes out what's left before it stops
 		Global.applicationQuitOrder = true;
+		StopLogService();
 		logservice.join();
 		return Result;
 	};