feat: 详情页作者名链接到 /space/:uid 空间页

- 作者名可点击跳转到作者空间页，已注销用户不生成链接
- hover 时变为主题紫色 + 下划线，与 meta 行风格协调

templates/MetaLab-2026/html/posts/show.html

@@ -8,7 +8,11 @@
         <header class="post-detail-header">
             <h1 class="post-detail-title">{{.Post.Title}}</h1>
             <div class="post-detail-meta">
-                <span>作者：{{if .Post.AuthorName}}{{.Post.AuthorName}}{{else}}该用户已注销{{end}}</span>
+                {{if .Post.AuthorName}}
+                <span>作者：<a href="/space/{{.Post.UserID}}" class="post-meta-author">{{.Post.AuthorName}}</a></span>
+                {{else}}
+                <span>作者：该用户已注销</span>
+                {{end}}
                 <span>阅读：{{.Post.ViewsCount}}</span>
                 <span>点赞：{{.Post.LikesCount}}</span>
                 <span>收藏：{{.Post.FavoritesCount}}</span>

templates/MetaLab-2026/static/css/posts.css

@@ -97,6 +97,16 @@
     color: #6b7280;
 }
 
+.post-detail-meta a {
+    color: #6b7280;
+    text-decoration: none;
+}
+
+.post-detail-meta a:hover {
+    color: #6366f1;
+    text-decoration: underline;
+}
+
 .post-detail-body {
     font-size: 16px;
     line-height: 1.8;