fix: 锁定机制不再改变帖子状态，锁定与退回独立

- Post 模型新增 IsLocked 字段，与 Status 解耦
- Lock 仅设 IsLocked=true（不改 Status），已通过帖子锁定后仍公开可见
- Unlock 仅设 IsLocked=false（不改 Status）
- Update/EditPage 编辑检查改用 IsLocked 而非 Status==locked
- Reject 与 Lock 独立，可单独退回或锁定+退回组合使用
- 新增 ErrPostCannotLock 错误哨兵
- 前端模板编辑按钮/锁定标识基于 IsLocked 渲染

internal/common/errors.go

@@ -42,5 +42,6 @@ var (
 	ErrPostCannotSubmit         = errors.New("仅草稿和已退回帖子可提交审核")
 	ErrPostCannotApprove        = errors.New("仅待审核帖子可通过")
 	ErrPostCannotReject         = errors.New("仅待审核和已发布帖子可退回")
+	ErrPostCannotLock           = errors.New("待审核帖子不允许锁定")
 	ErrPostCannotUnlock         = errors.New("仅锁定状态可解锁")
 )

internal/controller/admin/admin_post_controller.go

@@ -117,7 +117,7 @@ func (ctrl *AdminPostController) Lock(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.Lock(uint(id)); err != nil {
-		if errors.Is(err, common.ErrPostNotFound) {
+		if errors.Is(err, common.ErrPostNotFound) || errors.Is(err, common.ErrPostCannotLock) {
 			common.Error(c, http.StatusBadRequest, err.Error())
 		} else {
 			common.Error(c, http.StatusInternalServerError, "锁定失败")

internal/controller/post_controller.go

@@ -139,7 +139,7 @@ func (ctrl *PostController) EditPage(c *gin.Context) {
 	}
 
 	post, err := ctrl.postService.GetByID(uint(id))
-	if err != nil || post.Status == model.PostStatusPending || post.Status == model.PostStatusLocked {
+	if err != nil || post.Status == model.PostStatusPending || post.IsLocked {
 		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
 			"Title": "未找到或无法编辑",
 		}))

internal/model/post.go

@@ -14,6 +14,7 @@ type Post struct {
 	Excerpt      string         `gorm:"type:varchar(500)" json:"excerpt"` // plain text summary for list
 	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"`
 	RejectReason string         `gorm:"type:varchar(500);default:''" json:"reject_reason,omitempty"`
 	AllowComment bool           `gorm:"default:true" json:"allow_comment"`
 	DeletedAt    gorm.DeletedAt `gorm:"index" json:"-"`

internal/service/post_service.go

@@ -213,7 +213,7 @@ func (s *PostService) Update(postID uint, title, body string) error {
 		return err
 	}
 
-	if post.Status == model.PostStatusPending || post.Status == model.PostStatusLocked {
+	if post.Status == model.PostStatusPending || post.IsLocked {
 		return common.ErrPostCannotEdit
 	}
 
@@ -263,6 +263,7 @@ func (s *PostService) Approve(postID uint) error {
 }
 
 // Reject 退回：pending/approved → rejected
+// 独立于锁定：可单独退回（允许作者修改后重审），也可锁定+退回（禁止再投稿）
 func (s *PostService) Reject(postID uint, reason string) error {
 	post, err := s.findPost(postID)
 	if err != nil {
@@ -276,26 +277,30 @@ func (s *PostService) Reject(postID uint, reason string) error {
 	return s.repo.Update(post)
 }
 
-// Lock 锁定：任意状态 → locked（管理员可随时锁定）
+// 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 {
 	post, err := s.findPost(postID)
 	if err != nil {
 		return err
 	}
-	post.Status = model.PostStatusLocked
+	// 待审核帖子不允许锁定（审核流程中）
+	if post.Status == model.PostStatusPending {
+		return common.ErrPostCannotLock
+	}
+	post.IsLocked = true
 	return s.repo.Update(post)
 }
 
-// Unlock 解锁：locked → 草稿
+// Unlock 解锁：清除 IsLocked 标志，恢复可编辑
 func (s *PostService) Unlock(postID uint) error {
 	post, err := s.findPost(postID)
 	if err != nil {
 		return err
 	}
-	if post.Status != model.PostStatusLocked {
+	if !post.IsLocked {
 		return common.ErrPostCannotUnlock
 	}
-	post.Status = model.PostStatusDraft
+	post.IsLocked = false
 	return s.repo.Update(post)
 }
 

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

@@ -13,6 +13,9 @@
                 {{if ne .Post.Status "approved"}}
                 <span class="post-status post-status-{{.Post.Status}}">{{index $.StatusNames .Post.Status}}</span>
                 {{end}}
+                {{if .Post.IsLocked}}
+                <span class="post-status post-status-locked">已锁定</span>
+                {{end}}
             </div>
         </header>
 
@@ -27,7 +30,7 @@
 
     {{if .IsLoggedIn}}
     <div class="post-actions">
-        {{if and $.Post (or (eq $.Post.UserID $.UID) $.CanAccessAdmin) (ne $.Post.Status "pending") (ne $.Post.Status "locked")}}
+        {{if and $.Post (or (eq $.Post.UserID $.UID) $.CanAccessAdmin) (ne $.Post.Status "pending") (not $.Post.IsLocked)}}
         <a href="/posts/{{$.Post.ID}}/edit" class="btn btn-secondary">编辑</a>
         {{end}}
         {{if and $.Post (eq $.Post.UserID $.UID) (or (eq $.Post.Status "draft") (eq $.Post.Status "rejected"))}}

templates/admin/html/posts/index.html

@@ -13,7 +13,6 @@
                     <option value="pending" {{if eq .Status "pending"}}selected{{end}}>待审核</option>
                     <option value="approved" {{if eq .Status "approved"}}selected{{end}}>已发布</option>
                     <option value="rejected" {{if eq .Status "rejected"}}selected{{end}}>已退回</option>
-                    <option value="locked" {{if eq .Status "locked"}}selected{{end}}>已锁定</option>
                 </select>
                 <button type="submit" class="btn btn-primary">搜索</button>
             </form>
@@ -43,7 +42,7 @@
                     <td>{{.ID}}</td>
                     <td><a href="/posts/{{.ID}}" target="_blank" class="post-link">{{.Title}}</a></td>
                     <td>{{if .AuthorName}}{{.AuthorName}}({{.UserID}}){{else}}UID{{.UserID}}{{end}}</td>
-                    <td><span class="status-badge status-{{.Status}}">{{index $.StatusNames .Status}}</span></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>{{.CreatedAt.Format "2006-01-02 15:04"}}</td>
                     <td class="actions-cell">
                         <div class="action-btns">
@@ -54,10 +53,10 @@
                             {{if eq .Status "approved"}}
                             <button class="btn btn-sm btn-warning post-reject" data-id="{{.ID}}">退回</button>
                             {{end}}
-                            {{if and (ne .Status "locked") (ne .Status "pending")}}
+                            {{if and (not .IsLocked) (ne .Status "pending")}}
                             <button class="btn btn-sm btn-danger post-lock" data-id="{{.ID}}">锁定</button>
                             {{end}}
-                            {{if eq .Status "locked"}}
+                            {{if .IsLocked}}
                             <button class="btn btn-sm btn-success post-unlock" data-id="{{.ID}}">解锁</button>
                             {{end}}
                         </div>