fix(popover): keep the last-hovered row highlighted when the pointer leaves

The surface's onMouseLeave nulled hoverIndex, so moving the pointer off a menu snapped the highlight
back to activeIndex — the first item in a menu with a free-text input (ChannelTags), where the field
swallows arrow keys so there is no list-nav holding a keyboard position. The keyboard and typeahead
already reclaim the highlight by nulling hoverIndex in onNavigate/onMatch, so the mouseleave reset was
redundant; dropping it keeps the last hover. 0.60.3.

frontend/src/lib/releaseNotes.ts

@@ -14,6 +14,13 @@ export interface ReleaseEntry {
 }
 
 export const RELEASE_NOTES: ReleaseEntry[] = [
+  {
+    version: "0.60.3",
+    date: "2026-08-08",
+    fixes: [
+      "In a menu, the highlight now stays on the row you last hovered when you move the pointer off it, instead of snapping back to the first item.",
+    ],
+  },
   {
     version: "0.60.2",
     date: "2026-08-08",