feat(sw): footer command labels end in an ellipsis with a full-name tooltip

Same 68 x 47 slot and 14px label; without a title the full label is the native
tooltip only while it is cut. Accessible name unchanged, no new props.

packages/sw/src/theme/sw-footer.css

@@ -278,7 +278,9 @@
   overflow: hidden;
   line-height: 16px;
   text-align: center;
-  text-overflow: clip;
+  /* A command longer than the slot (POLYGON, WIPEOUT …) ends in … inside the same 64px; the full name stays the
+     accessible name and shows as the tooltip (SWFooterToolButton). Slot, font and centering are unchanged. */
+  text-overflow: ellipsis;
   white-space: nowrap;
   text-shadow: var(--hm-sw-header-text-outline);
 }