feat(compose): 正文内嵌隐藏块并升级 Markdown 编辑器

去掉整帖可见性表单，改为 :::hide 按块脱敏；工具栏补齐代码块、链接/图片对话框与粘贴拖拽上传。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/handler/post.go

@@ -96,8 +96,6 @@ type CreatePostRequest struct {
 	Content       string `json:"content" binding:"required,min=1"`
 	Tags          string `json:"tags"`
 	PostType      string `json:"post_type"`
-	ContentAccess string `json:"content_access"`
-	AccessPoints  int    `json:"access_points"`
 	TypeMeta      string `json:"type_meta"`
 	AttachmentIDs []uint `json:"attachment_ids"`
 }
@@ -118,8 +116,6 @@ func (h *Handlers) CreatePost(c *gin.Context) {
 		Content:       req.Content,
 		Tags:          req.Tags,
 		PostType:      req.PostType,
-		ContentAccess: req.ContentAccess,
-		AccessPoints:  req.AccessPoints,
 		TypeMeta:      req.TypeMeta,
 		Status:        status,
 		AttachmentIDs: req.AttachmentIDs,
@@ -141,8 +137,6 @@ type UpdatePostRequest struct {
 	Title         string  `json:"title" binding:"omitempty,min=1,max=256"`
 	Content       string  `json:"content" binding:"omitempty,min=1"`
 	Tags          string  `json:"tags"`
-	ContentAccess *string `json:"content_access"`
-	AccessPoints  *int    `json:"access_points"`
 	TypeMeta      *string `json:"type_meta"`
 	AttachmentIDs *[]uint `json:"attachment_ids"`
 }
@@ -165,8 +159,6 @@ func (h *Handlers) UpdatePost(c *gin.Context) {
 		Title:         req.Title,
 		Content:       req.Content,
 		Tags:          req.Tags,
-		ContentAccess: req.ContentAccess,
-		AccessPoints:  req.AccessPoints,
 		TypeMeta:      req.TypeMeta,
 		AttachmentIDs: req.AttachmentIDs,
 	})