.gpx-panel__action's own "display: flex" outranks the browser's
default "[hidden] { display: none }" -- same specificity, but an
author stylesheet rule always beats a user-agent one -- so setting
.hidden = true on these (GpxPanelControl#mount) never had any visual
effect. The per-file row icons (delete/download) were unaffected by
this since they're conditionally never added to the DOM at all rather
than hidden after the fact, a different mechanism that doesn't hit
this bug.
Same class of bug as the earlier Distance/Area overlap fix. Swept the
rest of the app's [hidden]-manipulated elements for the same pattern
(a display override with no [hidden] counterpart) -- this was the
only other one.
Verified in a real browser: computed display is now "none", not just
the hidden attribute being set with no visual effect.