style: 💄 fix z-index for rose-dialog modal (#2579)

ui/desktop/app/styles/app.scss

@@ -278,6 +278,11 @@
   text-align: center;
 }
 
+// Rose dialog - positioned above modal overlay
+.rose-dialog {
+  z-index: 6000;
+}
+
 // Overlay above everything - including notifications
 .rose-dialog-modal-overlay {
   z-index: 5500;