feat: 锁定文章需填写锁定理由，编辑器显示锁定理由

- Post 模型新增 LockReason 字段，锁定必填理由，解锁清空
- PostLockRequest DTO：reason 必填，1-500字
- Admin JS：锁定操作弹出 prompt 要求填写理由
- 编辑器锁定横幅显示"锁定理由：XXX"，理由为空时不显示该行

internal/controller/admin/admin_post_controller.go

@@ -116,7 +116,13 @@ func (ctrl *AdminPostController) Lock(c *gin.Context) {
 		return
 	}
 
-	if err := ctrl.postService.Lock(uint(id)); err != nil {
+	var req model.PostLockRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		common.Error(c, http.StatusBadRequest, "请填写锁定理由")
+		return
+	}
+
+	if err := ctrl.postService.Lock(uint(id), req.Reason); err != nil {
 		if errors.Is(err, common.ErrPostNotFound) || errors.Is(err, common.ErrPostCannotLock) {
 			common.Error(c, http.StatusBadRequest, err.Error())
 		} else {

internal/controller/admin/interfaces.go

@@ -42,7 +42,7 @@ type adminPostUseCase interface {
 	ListPendingRevisions(keyword string, page, pageSize int) ([]model.Post, int64, error)
 	Approve(postID uint) error
 	Reject(postID uint, reason string) error
-	Lock(postID uint) error
+	Lock(postID uint, reason string) error
 	Unlock(postID uint) error
 	Restore(postID uint) error
 }

internal/controller/studio_controller.go

@@ -154,7 +154,6 @@ func (ctrl *StudioController) WritePage(c *gin.Context) {
 					"Post":      post,
 					"ActiveTab": "write",
 					"ExtraCSS":  "/static/css/studio.css",
-					"StatusNames": common.PostStatusDisplayNames,
 				}))
 				return
 			}

internal/model/dto.go

@@ -47,6 +47,11 @@ type PostRejectRequest struct {
 	Reason string `json:"reason" binding:"required,min=1,max=500"`
 }
 
+// PostLockRequest 锁定请求
+type PostLockRequest struct {
+	Reason string `json:"reason" binding:"required,min=1,max=500"`
+}
+
 // PostListQuery 列表查询参数
 type PostListQuery struct {
 	Keyword  string `form:"keyword"`

internal/model/post.go

@@ -15,6 +15,7 @@ type Post struct {
 	UserID       uint           `gorm:"index;not null" json:"user_id"`
 	Status       string         `gorm:"type:varchar(20);index;default:draft;not null" json:"status"`
 	IsLocked     bool           `gorm:"default:false" json:"is_locked"`
+	LockReason   string         `gorm:"type:varchar(500);default:''" json:"lock_reason,omitempty"`
 	PendingTitle string         `gorm:"type:varchar(200);default:''" json:"pending_title,omitempty"`
 	PendingBody  string         `gorm:"type:text" json:"pending_body,omitempty"`
 	RejectReason string         `gorm:"type:varchar(500);default:''" json:"reject_reason,omitempty"`

internal/service/post_service.go

@@ -341,7 +341,7 @@ func (s *PostService) Reject(postID uint, reason string) error {
 }
 
 // Lock 锁定：设置 IsLocked 标志，禁止编辑，不改变帖子发布状态
-func (s *PostService) Lock(postID uint) error {
+func (s *PostService) Lock(postID uint, reason string) error {
 	post, err := s.findPost(postID)
 	if err != nil {
 		return err
@@ -351,6 +351,7 @@ func (s *PostService) Lock(postID uint) error {
 		return common.ErrPostCannotLock
 	}
 	post.IsLocked = true
+	post.LockReason = reason
 	return s.repo.Update(post)
 }
 
@@ -364,6 +365,7 @@ func (s *PostService) Unlock(postID uint) error {
 		return common.ErrPostCannotUnlock
 	}
 	post.IsLocked = false
+	post.LockReason = ""
 	return s.repo.Update(post)
 }