add: preparation page setup

src/app/prepare/page.tsx

@@ -0,0 +1,11 @@
+export default function Page() {
+  return (
+    <div
+      className="bg-[#f1f0f2] h-screen w-full flex flex-col gap-6 items-center justify-center"
+      data-tauri-drag-region
+    >
+      <h1 className="text-4xl font-bold tracking-wide text-zinc-800">CS工具箱</h1>
+      <p>准备环节</p>
+    </div>
+  )
+}