feat: allows keyboard navigation to switch from last to first (npmx-dev#1543)

Co-authored-by: TAKAHASHI Shuuji <id@shuuji3.xyz>

Author: btea

app/components/Compare/PackageSelector.vue

@@ -105,14 +105,20 @@ function handleKeydown(e: KeyboardEvent) {
     case 'ArrowDown':
       e.preventDefault()
       if (count === 0) return
-      highlightedIndex.value = Math.min(highlightedIndex.value + 1, count - 1)
+      if (highlightedIndex.value < count - 1) {
+        highlightedIndex.value++
+      } else {
+        highlightedIndex.value = 0
+      }
       break
 
     case 'ArrowUp':
       e.preventDefault()
       if (count === 0) return
       if (highlightedIndex.value > 0) {
         highlightedIndex.value--
+      } else {
+        highlightedIndex.value = count - 1
       }
       break