feat: 添加内容删除前检查，确保内容未被购买

backend/app/services/creator.go

@@ -425,6 +425,12 @@ func (s *creator) DeleteContent(ctx context.Context, userID int64, id string) er
 		return err
 	}
 
+	// Check if purchased (ContentAccess exists)
+	count, _ := models.ContentAccessQuery.WithContext(ctx).Where(models.ContentAccessQuery.ContentID.Eq(cid)).Count()
+	if count > 0 {
+		return errorx.ErrPreconditionFailed.WithMsg("该内容已被购买，无法删除")
+	}
+
 	_, err = models.ContentQuery.WithContext(ctx).
 		Where(models.ContentQuery.ID.Eq(cid), models.ContentQuery.TenantID.Eq(tid)).
 		Delete()

frontend/portal/src/views/creator/ContentsView.vue

@@ -131,6 +131,8 @@
             </div>
          </div>
       </div>
+
+      <ConfirmDialog />
    </div>
 </template>