feat: 文章标签展示、搜索框清除按钮

- 文章详情页和文章卡片展示标签
- 搜索框右侧添加 × 清除按钮
- 标签点击跳转文章列表页自动搜索
- 修复 hasAnyFilter 未包含 tags 的 bug

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pages/posts/[slug].vue

@@ -1,6 +1,7 @@
 <script setup lang="ts">
 import { siteConfig } from '~/config/site'
 
+const router = useRouter()
 const route = useRoute()
 const slug = route.params.slug as string
 
@@ -52,6 +53,17 @@ function formatDate(date: string) {
         {{ post.description }}
       </p>
 
+      <div v-if="post.tags?.length" class="mt-4 flex flex-wrap gap-2">
+        <span
+          v-for="tag in post.tags"
+          :key="tag"
+          class="tag-pill cursor-pointer"
+          @click="router.push(`/posts?tag=${encodeURIComponent(tag)}`)"
+        >
+          {{ tag }}
+        </span>
+      </div>
+
       <div v-if="post.image" class="mt-6">
         <img
           :src="post.image"