支持在线时间跨天并优化发布与筛选体验

允许在线时段 end 早于 start 表示跨天，统一展示「次日」文案；修复移动端价格区间清空后被 sessionStorage 回写；优化 PC/移动端在线时间控件密度与通栏展示。

backend/internal/modules/listing/service_test.go

@@ -93,7 +93,7 @@ func TestValidateRequiredOnlineTimeRejectsMissing(t *testing.T) {
 	}
 }
 
-func TestValidateRequiredOnlineTimeRejectsInvalidRange(t *testing.T) {
+func TestValidateRequiredOnlineTimeAllowsCrossDay(t *testing.T) {
 	req := CreateRequest{
 		AssetSummary: map[string]any{
 			"online_time": map[string]any{
@@ -103,6 +103,21 @@ func TestValidateRequiredOnlineTimeRejectsInvalidRange(t *testing.T) {
 		},
 	}
 
+	if err := validateRequiredOnlineTime(req); err != nil {
+		t.Fatalf("expected cross-day range to be valid, got %v", err)
+	}
+}
+
+func TestValidateRequiredOnlineTimeRejectsSameStartEnd(t *testing.T) {
+	req := CreateRequest{
+		AssetSummary: map[string]any{
+			"online_time": map[string]any{
+				"start": "10:00",
+				"end":   "10:00",
+			},
+		},
+	}
+
 	if err := validateRequiredOnlineTime(req); err != ErrInvalidOnlineTime {
 		t.Fatalf("expected ErrInvalidOnlineTime, got %v", err)
 	}