Make sure plan picker shows over split-pane splitter

Author: pimterry

src/components/account/plan-picker.tsx

@@ -24,7 +24,7 @@ const PlanPickerModal = styled.dialog`
     right: auto;
 
     transform: translate(-50%, -50%);
-    z-index: 99;
+    z-index: 9999;
 
     display: flex;
     flex-direction: row;