fix: default grok group media generation

backend/internal/service/admin_service.go

@@ -1804,6 +1804,12 @@ func defaultModelsListCandidateIDs(platform string) []string {
 	}
 }
 
+func defaultAllowImageGenerationForPlatform(platform string) bool {
+	// Grok image and video generation routes share the legacy image-generation gate.
+	// Older clients send the false zero value, so Grok groups must default enabled.
+	return platform == PlatformGrok
+}
+
 func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupInput) (*Group, error) {
 	if input.RateMultiplier <= 0 {
 		return nil, errors.New("rate_multiplier must be > 0")
@@ -1859,6 +1865,8 @@ func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupIn
 		mcpXMLInject = *input.MCPXMLInject
 	}
 
+	allowImageGeneration := input.AllowImageGeneration || defaultAllowImageGenerationForPlatform(platform)
+
 	// 如果指定了复制账号的源分组，先获取账号 ID 列表
 	var accountIDsToCopy []int64
 	if len(input.CopyAccountsFromGroupIDs) > 0 {
@@ -1902,7 +1910,7 @@ func (s *adminServiceImpl) CreateGroup(ctx context.Context, input *CreateGroupIn
 		DailyLimitUSD:                   dailyLimit,
 		WeeklyLimitUSD:                  weeklyLimit,
 		MonthlyLimitUSD:                 monthlyLimit,
-		AllowImageGeneration:            input.AllowImageGeneration,
+		AllowImageGeneration:            allowImageGeneration,
 		ImageRateIndependent:            input.ImageRateIndependent,
 		ImageRateMultiplier:             imageRateMultiplier,
 		ImagePrice1K:                    imagePrice1K,

backend/internal/service/admin_service_group_test.go

@@ -198,6 +198,40 @@ func TestAdminService_CreateGroup_NilImagePricing(t *testing.T) {
 	require.Nil(t, repo.created.ImagePrice4K)
 }
 
+func TestAdminService_CreateGroup_DefaultsGrokMediaGenerationEnabled(t *testing.T) {
+	repo := &groupRepoStubForAdmin{}
+	svc := &adminServiceImpl{groupRepo: repo}
+
+	group, err := svc.CreateGroup(context.Background(), &CreateGroupInput{
+		Name:           "grok-media",
+		Description:    "Grok media group",
+		Platform:       PlatformGrok,
+		RateMultiplier: 1.0,
+	})
+	require.NoError(t, err)
+	require.NotNil(t, group)
+	require.NotNil(t, repo.created)
+	require.True(t, repo.created.AllowImageGeneration)
+	require.True(t, group.AllowImageGeneration)
+}
+
+func TestAdminService_CreateGroup_PreservesNonGrokImageGenerationDisabled(t *testing.T) {
+	repo := &groupRepoStubForAdmin{}
+	svc := &adminServiceImpl{groupRepo: repo}
+
+	group, err := svc.CreateGroup(context.Background(), &CreateGroupInput{
+		Name:           "anthropic-text",
+		Description:    "Anthropic text group",
+		Platform:       PlatformAnthropic,
+		RateMultiplier: 1.0,
+	})
+	require.NoError(t, err)
+	require.NotNil(t, group)
+	require.NotNil(t, repo.created)
+	require.False(t, repo.created.AllowImageGeneration)
+	require.False(t, group.AllowImageGeneration)
+}
+
 // TestAdminService_UpdateGroup_WithImagePricing 测试更新分组时 ImagePrice 字段正确更新
 func TestAdminService_UpdateGroup_WithImagePricing(t *testing.T) {
 	existingGroup := &Group{