fix(queue): size the queue screen's way out for a thumb

Measured at 424x439: the three header actions were 25x21px. That
matters more than it looks, because with the panel spanning the whole
width the scrim underneath it has no uncovered pixels at all -- so the
close button is the only pointer route out of a full-screen surface,
and it was below the 24x24 floor in one dimension.

Sized only in overlay mode. Inline these sit in a 320px column beside
the content, where a mouse is what reaches them and 44px of header is
44px the queue does not get.

frontend/src/components/queue-panel/queue-panel.ts

@@ -410,6 +410,22 @@ export class QueuePanel
             :host([overlay]) .panel-content {
                 width: 100%;
             }
+
+            /* A screen's way out has to be hittable with a thumb.
+               Measured at 424x439 before #55: these were **25x21px**,
+               and with the panel spanning the whole width the scrim
+               underneath has no uncovered pixels at all -- so it was
+               the only pointer route out of a full-screen surface.
+               Back answers it now as well, which is the other half.
+
+               Sized only in overlay mode: inline these sit in a 320px
+               column beside the content, where a mouse is what reaches
+               them and 44px of header is 44px the queue does not get. */
+            :host([overlay]) .header-action-button {
+                min-width: 44px;
+                min-height: 44px;
+                justify-content: center;
+            }
         }
 
         .resize-handle {