fix: allow grok scheduler capability routing

backend/internal/service/account.go

@@ -1258,6 +1258,9 @@ func (a *Account) openAIEndpointCapabilitySet() (map[string]bool, bool) {
 }
 
 func (a *Account) SupportsOpenAIImageCapability(capability OpenAIImagesCapability) bool {
+	if capability == "" {
+		return true
+	}
 	if !a.IsOpenAI() {
 		return false
 	}

backend/internal/service/openai_account_scheduler_test.go

@@ -475,6 +475,50 @@ func TestOpenAIGatewayService_SelectAccountWithScheduler_DefaultDisabled_Embeddi
 	require.Equal(t, openAIAccountScheduleLayerLoadBalance, decision.Layer)
 }
 
+func TestOpenAIGatewayService_SelectAccountWithScheduler_DefaultDisabled_AllowsGrokChatAccount(t *testing.T) {
+	resetOpenAIAdvancedSchedulerSettingCacheForTest()
+
+	ctx := context.Background()
+	groupID := int64(10113)
+	accounts := []Account{
+		{
+			ID:          36041,
+			Platform:    PlatformGrok,
+			Type:        AccountTypeOAuth,
+			Status:      StatusActive,
+			Schedulable: true,
+			Concurrency: 1,
+			Priority:    0,
+		},
+	}
+	cfg := &config.Config{}
+	cfg.Gateway.Scheduling.LoadBatchEnabled = false
+	svc := &OpenAIGatewayService{
+		accountRepo:        schedulerTestOpenAIAccountRepo{accounts: accounts},
+		cache:              &schedulerTestGatewayCache{},
+		cfg:                cfg,
+		concurrencyService: NewConcurrencyService(schedulerTestConcurrencyCache{}),
+	}
+
+	selection, decision, err := svc.SelectAccountWithSchedulerForCapability(
+		ctx,
+		&groupID,
+		"",
+		"",
+		"grok-4.3",
+		nil,
+		OpenAIUpstreamTransportAny,
+		OpenAIEndpointCapabilityChatCompletions,
+		false,
+		PlatformGrok,
+	)
+	require.NoError(t, err)
+	require.NotNil(t, selection)
+	require.NotNil(t, selection.Account)
+	require.Equal(t, int64(36041), selection.Account.ID)
+	require.Equal(t, openAIAccountScheduleLayerLoadBalance, decision.Layer)
+}
+
 func TestOpenAIGatewayService_SelectAccountWithScheduler_EnabledUsesAdvancedPreviousResponseRouting(t *testing.T) {
 	resetOpenAIAdvancedSchedulerSettingCacheForTest()
 

backend/internal/service/openai_images_test.go

@@ -442,6 +442,16 @@ func TestAccountSupportsOpenAIImageCapability_OAuthSupportsNative(t *testing.T)
 	require.True(t, account.SupportsOpenAIImageCapability(OpenAIImagesCapabilityNative))
 }
 
+func TestAccountSupportsOpenAIImageCapability_EmptyRequirementDoesNotRejectGrok(t *testing.T) {
+	account := &Account{
+		Platform: PlatformGrok,
+		Type:     AccountTypeOAuth,
+	}
+
+	require.True(t, account.SupportsOpenAIImageCapability(""))
+	require.False(t, account.SupportsOpenAIImageCapability(OpenAIImagesCapabilityBasic))
+}
+
 func TestAccountSupportsOpenAIEndpointCapability(t *testing.T) {
 	t.Run("OpenAI APIKey 默认兼容 chat 和 embeddings", func(t *testing.T) {
 		account := &Account{