feat(page): add 404 not found view

src/views/NotFoundView.vue

@@ -0,0 +1,34 @@
+<script setup lang="ts">
+import { setPageMeta } from '@/utils/seo'
+setPageMeta({ title: '页面不存在' })
+</script>
+
+<template>
+  <div class="not-found">
+    <h1>404</h1>
+    <p>页面不存在或已被删除</p>
+    <router-link to="/">返回首页</router-link>
+  </div>
+</template>
+
+<style scoped>
+.not-found {
+  text-align: center;
+  padding: 80px 0;
+}
+
+.not-found h1 {
+  font-size: 48px;
+  margin: 0 0 12px;
+}
+
+.not-found p {
+  color: #5c6470;
+  margin: 0 0 20px;
+}
+
+.not-found a {
+  color: #3b82f6;
+  text-decoration: none;
+}
+</style>