Chore: 更新框架到 React Router 7

修复迁移到 Tailwind 4 之后的样式差异
修复 404 页面的异常并调整样式
优化分页器组件的无障碍化，Span 标签替换成 Button

app/components/layout/header.tsx

@@ -1,4 +1,4 @@
-import { NavLink } from "@remix-run/react";
+import { NavLink } from "react-router";
 
 const navItems = [
   { name: "首页", to: "/" },

app/components/layout/spinner.tsx

@@ -0,0 +1,9 @@
+import { useNavigation } from "react-router";
+
+export default function SpinnerBar() {
+  const navigation = useNavigation();
+
+  return navigation.state === "loading" ? (
+    <div className="spinner animate-spinner-bar h-1 z-20 fixed top-0 left-0 right-0 bg-orange-200" />
+  ) : null;
+}