feat(comments): 支持编辑与管理可见历史，采纳展示改用楼层号

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

backend/model/db.go

@@ -36,7 +36,7 @@ func InitDB(dsn string) error {
 	}
 
 	if err := db.AutoMigrate(
-		&User{}, &Board{}, &Post{}, &Comment{}, &RefreshToken{}, &Like{}, &Notification{}, &Checkin{},
+		&User{}, &Board{}, &Post{}, &Comment{}, &CommentEditHistory{}, &RefreshToken{}, &Like{}, &Notification{}, &Checkin{},
 		&Announcement{}, &SiteSetting{}, &Attachment{}, &UserBoard{}, &LoginLog{},
 		&ChatRoom{}, &ChatRoomMember{}, &ChatMessage{},
 		&PointLedger{}, &PostContentUnlock{}, &PostAttachment{}, &PostAttachmentUnlock{},