fix(studio): stop lane-header clicks from reaching the track row

The prev/next keyframe chevrons and the group toggle diamond let their
click bubble to the ancestor track row, so seeking to a keyframe also
reselected the track. The disclosure caret and the eye already stop it;
these now match.

Truncated labels (layer name, track label, group label, value readout)
also carry a title so the full text is reachable on hover.

packages/studio/src/player/components/LayerDisclosureRow.tsx

@@ -50,7 +50,9 @@ export function LayerDisclosureRow({
       >
         ◇
       </span>
-      <span className="min-w-0 flex-1 truncate font-medium">{name}</span>
+      <span className="min-w-0 flex-1 truncate font-medium" title={name}>
+        {name}
+      </span>
     </div>
   );
 }