feat: 走心评论（精选评论）+ 移动端评论框底栏布局修复

- 底栏：≤480px 压缩按钮内边距，SE 等小屏单行放下；换行时按钮组右对齐
- Worker：comments 加 is_featured；PUT /comments/:id 支持切换；新增公开接口
  GET /api/v2/featured/comments（排除悄悄话/待审/已删，服务端渲染 markdown）
- 前端：评论区注入「精选」按钮（回复右侧，仅管理员可见）
- 关于页：走心评论板块（标题寄语通栏 + 卡片瀑布流），排在热力图上方

themes/Ying/layouts/partials/footer.html

@@ -146,8 +146,10 @@
   {{/* 匿名评论开关 + 表情包最近使用 */}}
   {{ $anon := resources.Get "js/modules/comment-anonymous.js" }}
   {{ $emoRecent := resources.Get "js/modules/emoticon-recent.js" }}
+  {{/* 走心评论：管理员「精选」按钮 */}}
+  {{ $feat := resources.Get "js/modules/comment-featured.js" }}
 
-  {{ $pageScripts := slice $friendlink $autofill $anon $emoRecent $artalkModule $human $paragraphComments $reward | resources.Concat "js/page-only.js" | resources.Minify | resources.Fingerprint }}
+  {{ $pageScripts := slice $friendlink $autofill $anon $emoRecent $feat $artalkModule $human $paragraphComments $reward | resources.Concat "js/page-only.js" | resources.Minify | resources.Fingerprint }}
 
   <script defer src="{{ $pageScripts.RelPermalink }}"></script>
   <script>window._pageOnlyScriptUrl = '{{ $pageScripts.RelPermalink }}';</script>
@@ -162,8 +164,9 @@
   {{ $autofill := resources.Get "js/modules/comment-autofill.js" }}
   {{ $anon := resources.Get "js/modules/comment-anonymous.js" }}
   {{ $emoRecent := resources.Get "js/modules/emoticon-recent.js" }}
+  {{ $feat := resources.Get "js/modules/comment-featured.js" }}
 
-  {{ $pageScripts := slice $friendlink $autofill $anon $emoRecent $artalkModule $human $paragraphComments $reward | resources.Concat "js/page-only.js" | resources.Minify | resources.Fingerprint }}
+  {{ $pageScripts := slice $friendlink $autofill $anon $emoRecent $feat $artalkModule $human $paragraphComments $reward | resources.Concat "js/page-only.js" | resources.Minify | resources.Fingerprint }}
 
   <script>window._pageOnlyScriptUrl = '{{ $pageScripts.RelPermalink }}';</script>
 {{ end }}