Release v0.6.3: fix capture banner ordering and check updates periodically

tests/screenshot_ui.cpp

@@ -165,8 +165,12 @@ int main()
         require(!IsWindow(window),"copied screenshot closes without confirmation");
         static bool published=false;
         static bool notificationAccepted=false;
+        static HWND notificationWindow{};
+        static bool expectHidden=false;
         app.notify=[](const ks::Clip &) {
             if(!published) throw std::runtime_error("notification preceded clipboard publication");
+            if(expectHidden && IsWindowVisible(notificationWindow))
+                throw std::runtime_error("selection overlay is still visible when notification is sent");
             return notificationAccepted;
         };
         for(bool autoOpen : {true,false}) for (bool accepted : {true, false}) {
@@ -178,6 +182,8 @@ int main()
             PatBlt(selection.image->dc,0,0,100,100,WHITENESS);
             selection.start={10,20}; selection.end={70,60};
             auto overlay=CreateWindowW(cls.lpszClassName,L"Selection test",WS_POPUP,0,0,100,100,app.window,nullptr,app.instance,&selection);
+            notificationWindow=overlay; expectHidden=!autoOpen;
+            ShowWindow(overlay,SW_SHOWNOACTIVATE);
             ks::finishSelection(overlay,selection,[](HWND,const ks::Clip &clip)->DWORD {
                 auto pixels=ks::decodeImage(clip);
                 if(pixels.width!=60 || pixels.height!=40) throw std::runtime_error("automatic copy did not crop selection");