Ask the client for frames between its steps

The frame pacer repaints the client's 3D windows at the user's frame rate
(HKCU\Software\T5DE\Graphics\FrameRate: 30, the default, adds nothing; 60, 120,
240, 360; 0 uncapped), so the client draws frames between its 30-per-second
steps. Only when affordable: a window is asked once its last frame is drawn,
and only if its frames take under three quarters of the interval; uncapped,
the client is left idle a third of a frame between frames. The engine's stats
now log frames per second.

The extra frames show the same scene for now.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

adapter/plugin.cpp

@@ -64,7 +64,7 @@ extern "C" imvu::SharedPtr<imvu::PiRenderEngine> __cdecl createRenderEngine(imvu
         const protocol::View shown = view();
         auto renderer = hwnd != nullptr && shown != protocol::View::Off ? RendererProcess::start(hwnd, shown) : nullptr;
         return imvu::SharedPtr<imvu::PiRenderEngine>(std::make_unique<Engine>(
-            std::move(inner), std::make_shared<Recorder>(std::move(renderer))));
+            std::move(inner), std::make_shared<Recorder>(std::move(renderer)), hwnd));
     } catch (const std::exception& e) {
         // Exceptions mustn't cross into IMVU's code (a different C++ runtime).
         log::info("createRenderEngine failed: {}", e.what());