init(server/game): rewrite the server in c++

tests/harness.h

@@ -0,0 +1,15 @@
+#pragma once
+
+// Shared by the test translation units; test_main.cpp owns the counters and main().
+namespace testing {
+
+void check(bool ok, const char* what);
+int failures();
+int checks();
+
+}  // namespace testing
+
+// One entry point per file, called in order from main().
+void runGameTests();
+void runHttpTests();
+void runFlowTests();