fix: address assistant review feedback

apps/nextjs/src/components/board/items/actions/test/empty-position.spec.ts

@@ -18,6 +18,7 @@ describe("get first empty position", () => {
       0,
     ],
     [[["a", "a", "a", "a"]], [1, 1], 0, 1],
+    [[["a", " ", " ", " "]], [4, 1], 0, 1],
     [
       [
         ["a", "a", "a", "a"],