fix: channel cache fail-close, group conflict check across pages, status toggle stale data

- GetGroupPlatforms failure now stores error-TTL cache and returns error (fail-close)
- Frontend group-to-channel conflict map loads all channels instead of current page only
- Toggle channel status reloads list when active filter would hide the changed item

backend/internal/repository/channel_repo.go

@@ -188,7 +188,7 @@ func (r *channelRepository) List(ctx context.Context, params pagination.Paginati
 	// 查询 channel 列表
 	dataQuery := fmt.Sprintf(
 		`SELECT c.id, c.name, c.description, c.status, c.model_mapping, c.billing_model_source, c.restrict_models, c.created_at, c.updated_at
-		 FROM channels c WHERE %s ORDER BY c.id DESC LIMIT $%d OFFSET $%d`,
+		 FROM channels c WHERE %s ORDER BY c.id ASC LIMIT $%d OFFSET $%d`,
 		whereClause, argIdx, argIdx+1,
 	)
 	args = append(args, pageSize, offset)

backend/internal/service/channel_service.go

@@ -278,7 +278,10 @@ func (s *ChannelService) buildCache(ctx context.Context) (*channelCache, error)
 		groupPlatforms, err = s.repo.GetGroupPlatforms(dbCtx, allGroupIDs)
 		if err != nil {
 			slog.Warn("failed to load group platforms for channel cache", "error", err)
-			// 降级：继续构建缓存但无法按平台过滤
+			errorCache := newEmptyChannelCache()
+			errorCache.loadedAt = time.Now().Add(-(channelCacheTTL - channelErrorTTL))
+			s.cache.Store(errorCache)
+			return nil, fmt.Errorf("get group platforms: %w", err)
 		}
 	}
 

backend/internal/service/channel_service_test.go

@@ -1182,12 +1182,15 @@ func TestBuildCache_GroupPlatformError(t *testing.T) {
 	}
 	svc := newTestChannelService(repo)
 
-	// Should degrade gracefully: channel is found, but without platform info
-	// pricing won't match because platform will be "" and pricing platform is "anthropic"
+	// Should fail-close: error propagated when group platforms cannot be loaded
 	result, err := svc.GetChannelForGroup(context.Background(), 10)
-	require.NoError(t, err)
-	require.NotNil(t, result) // channel still found
-	require.Equal(t, int64(1), result.ID)
+	require.Error(t, err)
+	require.Nil(t, result)
+
+	// Within error-TTL, second call should hit cache (empty) and return nil, nil
+	result2, err2 := svc.GetChannelForGroup(context.Background(), 10)
+	require.NoError(t, err2)
+	require.Nil(t, result2)
 }
 
 func TestBuildCache_MultipleGroupsSameChannel(t *testing.T) {