fix(mobile): keep the press transition to the press's own properties

`all` also sped up Run's mode colours, Stop's confirming state and the armed Ctrl key. The browser test now reads the transition at rest, since its 250ms hold would also pass the old 0.2s one.

src/web/public/mobile.css

@@ -3480,14 +3480,15 @@ html:is([data-skin="paper-gray"], [data-skin="solarized-light"], [data-skin="cat
      hover rules own box-shadow, so a background or shadow :active lost to them
      on every non-og skin. Nothing on these buttons sets transform or filter
      (the base .btn-toolbar:active nudge sits at lower specificity), so one rule
-     reads the same on all of them. 80ms so a quick tap shows the press at all. */
+     reads the same on all of them. 80ms so a quick tap shows the press at all,
+     on the press's own properties rather than `all`. */
   .toolbar .btn-toolbar,
   .btn-voice-mobile,
   .btn-attach-mobile,
   .btn-settings-mobile,
   .accessory-btn {
     -webkit-tap-highlight-color: transparent;
-    transition: all 80ms ease;
+    transition: transform 80ms ease, filter 80ms ease, background-color 80ms ease, border-color 80ms ease;
   }
 
   .toolbar .btn-toolbar:active,