chore: remove unused useForceUpdate.js (the .ts implementation is the one imported)

Fixes #87

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/hooks/useForceUpdate.js

@@ -1,12 +0,0 @@
-import { useState } from 'react';
-
-export function useForceUpdate() {
-  const [data, setData] = useState(null);
-
-  return [
-    data,
-    function forceUpdateHook() {
-      setData({});
-    },
-  ];
-}