fix: verify the window's real client rect before trusting size-to-window

The previous commit treated any Width==0 && Height==0 descriptor with a non-null
OutputWindow as "size to window" and wrapped it as if it were the game's real
swapchain. That's not quite safe: a helper/overlay swapchain (Steam, Discord,
NVIDIA overlay, etc.) could use this exact same 0x0 idiom against its own
tiny/hidden window, and would now get misclassified as the real swapchain instead
of correctly falling through to the existing "Overlay call!" path.

Check GetClientRect() on OutputWindow instead of just checking the pointer is
non-null: a hidden helper window resolves to a tiny or zero client rect, while a
game's actual window won't. Only treat the descriptor as size-to-window when the
window itself is at least 100x100.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: janblade

OptiScaler/hooks/DxgiFactory_Hooks.cpp

@@ -285,8 +285,22 @@ HRESULT DxgiFactoryHooks::CreateSwapChain(IDXGIFactory* realFactory, IUnknown* p
     // exactly this way and was previously being misclassified as "Overlay call!" and passed through
     // unwrapped, which is why the menu/toast overlay never appeared. Only a genuinely tiny, non-zero
     // descriptor (Steam/Discord-style overlay helper swapchains) should still take that path.
-    bool sizeToWindow =
-        pDesc->BufferDesc.Width == 0 && pDesc->BufferDesc.Height == 0 && pDesc->OutputWindow != nullptr;
+    //
+    // A non-null OutputWindow alone isn't enough to trust, though: a helper/overlay swapchain could
+    // use this exact same 0x0 idiom against its OWN tiny/hidden window. Check the window's real
+    // client rect rather than trusting the pointer -- a hidden helper window resolves to a tiny or
+    // zero rect; the game's actual window won't.
+    bool sizeToWindow = false;
+    if (pDesc->BufferDesc.Width == 0 && pDesc->BufferDesc.Height == 0 && pDesc->OutputWindow != nullptr)
+    {
+        RECT clientRect {};
+        if (GetClientRect(pDesc->OutputWindow, &clientRect))
+        {
+            auto windowWidth = clientRect.right - clientRect.left;
+            auto windowHeight = clientRect.bottom - clientRect.top;
+            sizeToWindow = windowWidth >= 100 && windowHeight >= 100;
+        }
+    }
 
     if (!sizeToWindow && (pDesc->BufferDesc.Height < 100 || pDesc->BufferDesc.Width < 100))
     {