Add sscl::co::syncAwaitNonViralCoro for blocking non-viral coroutine launch.

Co-authored-by: Cursor <cursoragent@cursor.com>

include/spinscale/co/syncAwaitNonViralCoro.h

@@ -0,0 +1,43 @@
+#ifndef SYNC_AWAIT_NON_VIRAL_CORO_H
+#define SYNC_AWAIT_NON_VIRAL_CORO_H
+
+#include <boostAsioLinkageFix.h>
+
+#include <spinscale/componentThread.h>
+#include <spinscale/co/nonViralTaskNursery.h>
+#include <exception>
+#include <functional>
+
+namespace sscl::co {
+
+/** Launch a non-viral coroutine on the current ComponentThread io_context and
+ * block until it settles, rethrowing any stored exception.
+ */
+template<typename InvokerFactory>
+void syncAwaitNonViralCoro(InvokerFactory&& _invokerFactory)
+{
+	std::exception_ptr slotException;
+
+	NonViralTaskNursery nursery;
+	nursery.openAdmission();
+	nursery.launch(
+		[&_invokerFactory](NonViralTaskNursery::Slot::Lease& lease)
+		{
+			return _invokerFactory(lease);
+		},
+		[&slotException](std::exception_ptr& exceptionPtr)
+		{
+			slotException = exceptionPtr;
+		});
+	nursery.closeAdmission();
+	nursery.syncAwaitAllSettlements(
+		sscl::ComponentThread::getSelf()->getIoContext());
+
+	if (slotException) {
+		std::rethrow_exception(slotException);
+	}
+}
+
+} // namespace sscl::co
+
+#endif // SYNC_AWAIT_NON_VIRAL_CORO_H