feat: 添加内容可见性字段和过滤选项，优化内容列表查询功能

backend/app/services/creator.go

@@ -121,6 +121,12 @@ func (s *creator) ListContents(
 	if filter.Status != nil && *filter.Status != "" {
 		q = q.Where(tbl.Status.Eq(consts.ContentStatus(*filter.Status)))
 	}
+	if filter.Visibility != nil && *filter.Visibility != "" {
+		q = q.Where(tbl.Visibility.Eq(consts.ContentVisibility(*filter.Visibility)))
+	}
+	if filter.Visibility != nil && *filter.Visibility != "" {
+		q = q.Where(tbl.Visibility.Eq(consts.ContentVisibility(*filter.Visibility)))
+	}
 	if filter.Genre != nil && *filter.Genre != "" {
 		val := *filter.Genre
 		if cn, ok := genreMap[val]; ok {
@@ -208,6 +214,7 @@ func (s *creator) ListContents(
 			VideoCount:  videoCount,
 			AudioCount:  audioCount,
 			Status:      string(item.Status),
+			Visibility:  string(item.Visibility),
 			CreatedAt:   item.CreatedAt.Format("2006-01-02 15:04"),
 			IsPinned:    item.IsPinned,
 			IsPurchased: false,