Focus the last menu item on ArrowUp

With nothing focused yet, ArrowUp landed on the second to last item.

src/lib/menuNavigation.ts

@@ -8,7 +8,7 @@ export function menuFocusIndex(
     case "ArrowDown":
       return wrap(current + 1);
     case "ArrowUp":
-      return wrap(current - 1);
+      return current === -1 ? count - 1 : wrap(current - 1);
     case "Home":
       return 0;
     case "End":

tests/unit/menuNavigation.test.ts

@@ -6,6 +6,7 @@ test.each([
   ["ArrowDown", -1, 0],
   ["ArrowDown", 0, 1],
   ["ArrowDown", 2, 0],
+  ["ArrowUp", -1, 2],
   ["ArrowUp", 0, 2],
   ["ArrowUp", 2, 1],
   ["Home", 1, 0],