feat: remove window_size plugin.

app/lib/constants/constants.dart

@@ -14,6 +14,8 @@ const longDuration = const Duration(milliseconds: 500);
 
 const minWindowSize = const Size(800, 600);
 
+const defaultWindowSize = const Size(1120, 720);
+
 const double defaultBorderRadius = 8;
 
 const double defaultButtonHeight = 36;

app/lib/constants/sp_keys.dart

@@ -1,4 +1,4 @@
 class SPKeys {
   static final String brightnessMode = 'BRIGHTNESS_MODE';
   static final String userLanguage = 'USER_LANGUAGE';
-}
+}