[fix] errors with default empty steam users + loading process

src/components/window/Header.tsx

@@ -6,10 +6,10 @@ const Header = () => {
   return (
     <div className="pt-6 select-none pb-9" data-tauri-drag-region>
       <h1 className="text-xl font-medium tracking-wide w-fit">
-        {steam.currentUser().personaName || 'CS工具箱'}
+        {steam.currentUser()?.personaName || 'CS工具箱'}
       </h1>
       <p className="text-sm font-light tracking-wide text-zinc-400 w-fit">
-        {steam.currentUser().accountName || '本周使用CS工具箱 114 小时'}
+        {steam.currentUser()?.accountName || '本周使用CS工具箱 114 小时'}
       </p>
     </div>
   )