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

internal/controller/interfaces.go

@@ -42,9 +42,9 @@ type postUseCase interface {
 
 // studioUseCase StudioController 对 PostService 的最小依赖（ISP：9 个方法）
 type studioUseCase interface {
-	Create(userID uint, title, body string) (*model.Post, error)
+	Create(userID uint, title, body, visibility, postType, reprintSource, declaration string, reprintProhibited bool) (*model.Post, error)
 	GetByID(id uint) (*model.Post, error)
-	Update(postID uint, title, body string) error
+	Update(postID uint, title, body, visibility, postType, reprintSource, declaration string, reprintProhibited bool) error
 	Delete(postID uint) error
 	SubmitForAudit(postID uint) error
 	ListByUser(userID uint, status string, page, pageSize int) ([]model.Post, int64, error)