feat: 文章属性前端完成 — Phase 3

- 写文章页：可见性/类型/转载来源/创作声明/禁止转载 属性表单
- 类型切换联动（转载显示来源，原创显示禁止转载复选框）
- 文章详情页：私密角标、置顶标记、创作声明横幅、转载来源
- 管理后台：置顶/取消置顶操作按钮
- PostService Create/Update 签名扩展接受文章属性
- DTO/接口同步更新

templates/admin/html/posts/index.html

@@ -42,7 +42,7 @@
                     <td>{{.ID}}</td>
                     <td><a href="/posts/{{.ID}}" target="_blank" class="post-link">{{.Title}}</a>{{if .PendingBody}} <span class="revision-badge">修订中</span>{{end}}</td>
                     <td>{{if .AuthorName}}{{.AuthorName}}({{.UserID}}){{else}}UID{{.UserID}}{{end}}</td>
-                    <td><span class="status-badge status-{{.Status}}">{{index $.StatusNames .Status}}</span>{{if .IsLocked}} <span class="status-badge status-locked">已锁定</span>{{end}}</td>
+                    <td><span class="status-badge status-{{.Status}}">{{index $.StatusNames .Status}}</span>{{if .IsLocked}} <span class="status-badge status-locked">已锁定</span>{{end}}{{if .PinType}} <span class="status-badge status-pinned">📌</span>{{end}}</td>
                     <td>{{.CreatedAt.Format "2006-01-02 15:04"}}</td>
                     <td class="actions-cell">
                         <div class="action-btns">
@@ -63,6 +63,14 @@
                             {{if .IsLocked}}
                             <button class="btn btn-sm btn-success post-unlock" data-id="{{.ID}}">解锁</button>
                             {{end}}
+                            {{if eq .Status "approved"}}
+                            {{if not .PinType}}
+                            <button class="btn btn-sm btn-info post-pin" data-id="{{.ID}}" data-pin-type="global">全局置顶</button>
+                            <button class="btn btn-sm btn-info post-pin" data-id="{{.ID}}" data-pin-type="category">分类置顶</button>
+                            {{else}}
+                            <button class="btn btn-sm btn-secondary post-unpin" data-id="{{.ID}}">取消置顶</button>
+                            {{end}}
+                            {{end}}
                         </div>
                     </td>
                 </tr>