增加公告图片编辑, 增加取消归档

backend/internal/modules/announcement/repository.go

@@ -179,6 +179,17 @@ func (r *Repository) Archive(ctx context.Context, id uint64) error {
 		Update("status", "archived").Error
 }
 
+// Unarchive 取消归档公告，恢复为已发布状态
+func (r *Repository) Unarchive(ctx context.Context, id uint64) error {
+	now := time.Now()
+	return r.db.WithContext(ctx).Model(&model.Announcement{}).
+		Where("id = ?", id).
+		Updates(map[string]interface{}{
+			"status":       "published",
+			"published_at": gorm.Expr("COALESCE(published_at, ?)", now),
+		}).Error
+}
+
 // Delete 删除公告
 func (r *Repository) Delete(ctx context.Context, id uint64) error {
 	return r.db.WithContext(ctx).Where("id = ?", id).Delete(&model.Announcement{}).Error