feat: 类型帖互动、积分经济与发帖体验

补齐问答采纳/重开、投票匿名与有票禁编、悬赏过期退回、抽奖回帖开奖，并接入积分账本与发帖附件可见性。

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

backend/handler/handlers.go

@@ -22,6 +22,8 @@ type Handlers struct {
 	Checkin      *service.CheckinService
 	Announcement *service.AnnouncementService
 	Upload       *service.UploadService
+	PostFile     *service.PostFileService
+	Points       *service.PointsService
 	Setting      *service.SettingService
 	AdminUser    *service.AdminUserService
 	Moderation   *service.ModerationService