Add an assert check to make sure no threads scheduled in nonauth model

luprex/core/cpp/world.hpp

@@ -264,6 +264,10 @@ public:
     int64_t alloc_id_predictable();
     
 private:
+    // Add a thread to the scheduler queue.
+    //
+    void schedule(int64_t clk, int64_t thid, int64_t plid);
+
     // Store a pointer to a world model into a lua registry.
     //
     static void store_global_pointer(lua_State *L, World *w);