refactor: 彻底移除 /posts/new 旧编辑器，统一迁移至 /studio/write

- 删除 /posts/new 路由，不再保留任何兼容层
- /posts/:id/edit 改为 301 跳转 /studio/write?id=:id
- 删除 posts/new.html 模板和 editor.js
- 移除 PostController.EditPage/Create/Update/Delete 孤儿方法
- 移除 /api/posts POST/PUT/DELETE 孤儿 API（保留 submit 和 upload-image）
- posts/show.html 编辑链接指向 /studio/write

internal/controller/post_controller.go

@@ -135,147 +135,6 @@ func (ctrl *PostController) ShowPage(c *gin.Context) {
 	}))
 }
 
-// EditPage 编辑页面
-func (ctrl *PostController) EditPage(c *gin.Context) {
-	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
-	if err != nil {
-		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
-			"Title":    "未找到",
-			"ExtraCSS": "/static/css/posts.css",
-		}))
-		return
-	}
-
-	post, err := ctrl.postService.GetByID(uint(id))
-	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",
-			"ExtraCSS": "/static/css/posts.css",
-		}))
-		return
-	}
-
-	uid, role, _ := common.GetGinUser(c)
-	if !ctrl.postService.IsPostAccessible(uid, role, post.UserID) {
-		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
-			"Title":    "未找到",
-			"ExtraCSS": "/static/css/posts.css",
-		}))
-		return
-	}
-
-	// 已通过帖子有待审修订时，编辑页展示待审内容
-	if post.PendingBody != "" {
-		post.Title = post.PendingTitle
-		post.Body = post.PendingBody
-	}
-
-	c.HTML(http.StatusOK, "posts/new.html", common.BuildPageData(c, gin.H{
-		"Title":    "编辑帖子",
-		"Post":     post,
-		"ExtraCSS": "/static/css/posts.css",
-	}))
-}
-
-// Create API 发帖
-func (ctrl *PostController) Create(c *gin.Context) {
-	uid, _, ok := common.GetGinUser(c)
-	if !ok {
-		common.Error(c, http.StatusUnauthorized, "请先登录")
-		return
-	}
-
-	var req model.PostCreateRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		common.Error(c, http.StatusBadRequest, "标题和正文不能为空")
-		return
-	}
-
-	post, err := ctrl.postService.Create(uid, req.Title, req.Body)
-	if err != nil {
-		common.Error(c, http.StatusInternalServerError, "发帖失败")
-		return
-	}
-
-	common.OkWithMessage(c, post, "发布成功")
-}
-
-// Update API 编辑帖子
-func (ctrl *PostController) Update(c *gin.Context) {
-	uid, role, ok := common.GetGinUser(c)
-	if !ok {
-		common.Error(c, http.StatusUnauthorized, "请先登录")
-		return
-	}
-
-	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
-	if err != nil {
-		common.Error(c, http.StatusBadRequest, "无效的帖子 ID")
-		return
-	}
-
-	var req model.PostUpdateRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		common.Error(c, http.StatusBadRequest, "标题和正文不能为空")
-		return
-	}
-
-	if _, ok := ctrl.getPostAndCheckAccess(uint(id), c, uid, role); !ok {
-		return
-	}
-
-	if err := ctrl.postService.Update(uint(id), req.Title, req.Body); err != nil {
-		if errors.Is(err, common.ErrPostCannotEdit) {
-			common.Error(c, http.StatusBadRequest, err.Error())
-		} else {
-			common.Error(c, http.StatusInternalServerError, "编辑失败")
-		}
-		return
-	}
-
-	common.OkMessage(c, "编辑成功")
-}
-
-// Delete API 删除帖子
-func (ctrl *PostController) Delete(c *gin.Context) {
-	uid, role, ok := common.GetGinUser(c)
-	if !ok {
-		common.Error(c, http.StatusUnauthorized, "请先登录")
-		return
-	}
-
-	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
-	if err != nil {
-		common.Error(c, http.StatusBadRequest, "无效的帖子 ID")
-		return
-	}
-
-	if _, ok := ctrl.getPostAndCheckAccess(uint(id), c, uid, role); !ok {
-		return
-	}
-
-	if err := ctrl.postService.Delete(uint(id)); err != nil {
-		common.Error(c, http.StatusInternalServerError, "删除失败")
-		return
-	}
-
-	common.OkMessage(c, "删除成功")
-}
-
-// getPostAndCheckAccess 获取帖子并检查当前用户权限
-// 返回 (*model.Post, true) 表示通过；返回 (nil, false) 表示已写入错误响应
-func (ctrl *PostController) getPostAndCheckAccess(id uint, c *gin.Context, uid uint, role string) (*model.Post, bool) {
-	post, err := ctrl.postService.GetByID(id)
-	if err != nil {
-		common.Error(c, http.StatusNotFound, "帖子不存在")
-		return nil, false
-	}
-	if !ctrl.postService.IsPostAccessible(uid, role, post.UserID) {
-		common.Error(c, http.StatusForbidden, "无权操作此帖子")
-		return nil, false
-	}
-	return post, true
-}
 
 // Submit API 提交审核
 func (ctrl *PostController) Submit(c *gin.Context) {