feat: 二级导航、豆瓣适配页、可关闭署名与全站统计

- 一级菜单子项渲染为下拉二级导航（移动端嵌套展开）
- 新增 douban.html 豆瓣收藏适配页（plugin-douban，分栏展示书影音）
- 页脚署名改为可配置名称且可关闭（默认「暖心向阳335」）
- 页脚全站数据统计可配置（文章/分类/标签/评论/访问/字数）
- 文章卡片字数+阅读时长增加 show_word_count 开关
- 修复 SinglePage 描述取用错误（spec.description -> status.excerpt）导致的 /weread、/subscriptions 白屏
- 修复 post-meta 静态类调用被禁（BigInteger.valueOf）导致的首页 500
- 文章分类链接增加间距

Co-Authored-By: WorkBuddy <noreply@workbuddy.ai>

src/modules/post-meta.html

@@ -23,17 +23,21 @@
       >1 views</span
     >
   </th:block>
-  <th:block th:if="${pluginFinder.available('extra-api')}">
+  <th:block
+    th:if="${pluginFinder.available('extra-api') and theme.config?.basic?.show_word_count != false}"
+  >
     <th:block th:with="wc=${extraApiStatsFinder.getPostWordCount({name: post.metadata.name})}">
       <th:block th:if="${wc != null and wc > 0}">
-        <span class="post-meta-sep">·</span>
-        <span class="post-words" th:text="#{post.words(${wc})}">字数</span>
-        <span class="post-meta-sep">·</span>
-        <span
-          class="post-reading"
-          th:text="#{post.reading_time(${#numbers.formatInteger((wc + 399).divide(java.math.BigInteger.valueOf(400)), 0)})}"
-          >阅读时长</span
-        >
+        <th:block th:with="rt=${(wc.longValue() + 399) / 400}">
+          <span class="post-meta-sep">·</span>
+          <span class="post-words" th:text="#{post.words(${wc.longValue()})}">字数</span>
+          <span class="post-meta-sep">·</span>
+          <span
+            class="post-reading"
+            th:text="#{post.reading_time(${rt})}"
+            >阅读时长</span
+          >
+        </th:block>
       </th:block>
     </th:block>
   </th:block>