ios: prevent context menu showing on images/icons long-tap

Author: shonsirsha

frontends/web/src/style/base.css

@@ -70,6 +70,10 @@ button {
     -webkit-user-select: none;
 }
 
+img {
+    -webkit-touch-callout: none;
+}
+
 svg {
     stroke-width: 1.6 !important;
 }