fix: Keep tooltips off touch devices

A tooltip triggered by hover and focus also fires on a tap, because tapping a
button focuses it. On a phone the hint then covers the thing that was just
pressed, and it stays there until something else takes focus. There is no
moment before a click for it to fill.

`IS_TOUCH_PRIMARY` reads `(hover: none)` once at load, the way `IS_MAC` reads
the platform, and the tooltip renders its trigger bare when it is set.

client/src/constants/Config.js

@@ -18,6 +18,11 @@ const MAX_SIZE_TO_DISPLAY_CONTENT = 256 * 1024;
 
 const IS_MAC = navigator.platform.startsWith('Mac');
 
+// Where the pointer cannot hover there is no room for a tooltip: a tap gives the
+// button focus, and a hint meant for the moment before a click ends up covering
+// the thing that was just clicked.
+const IS_TOUCH_PRIMARY = window.matchMedia('(hover: none)').matches;
+
 export default {
   BASE_PATH,
   ACCESS_TOKEN_KEY,
@@ -29,4 +34,5 @@ export default {
   ACTIVITIES_LIMIT,
   MAX_SIZE_TO_DISPLAY_CONTENT,
   IS_MAC,
+  IS_TOUCH_PRIMARY,
 };

client/src/lib/custom-ui/components/Tooltip/Tooltip.jsx

@@ -7,6 +7,8 @@ import React, { useMemo } from 'react';
 import PropTypes from 'prop-types';
 import { Popup as SemanticUIPopup } from 'semantic-ui-react';
 
+import Config from '../../../../constants/Config';
+
 import styles from './Tooltip.module.css';
 
 const callAll =
@@ -32,7 +34,7 @@ const Tooltip = React.forwardRef(
       });
     }, [children, content, props, ref, ariaLabel, onClick]);
 
-    if (disabled || !content) {
+    if (disabled || !content || Config.IS_TOUCH_PRIMARY) {
       return trigger;
     }