fix: resolve CI failures — gofmt, unused functions, missing test helpers

- Run gofmt on user schema, config test, group handler
- Remove unused mergeGroupIDs function
- Restore shared test helpers (newJSONResponse, queuedHTTPUpstream)
  that were in deleted Sora test file

backend/ent/schema/user.go

@@ -72,7 +72,6 @@ func (User) Fields() []ent.Field {
 		field.Time("totp_enabled_at").
 			Optional().
 			Nillable(),
-
 	}
 }
 

backend/internal/config/config_test.go

@@ -1554,7 +1554,6 @@ func TestValidateConfig_LogRequiredAndRotationBounds(t *testing.T) {
 	}
 }
 
-
 func TestLoad_DefaultGatewayUsageRecordConfig(t *testing.T) {
 	resetViperWithJWTSecret(t)
 	cfg, err := Load()

backend/internal/handler/admin/account_handler.go

@@ -1641,25 +1641,6 @@ func (h *AccountHandler) ResetQuota(c *gin.Context) {
 	response.Success(c, h.buildAccountResponseWithRuntime(c.Request.Context(), account))
 }
 
-// mergeGroupIDs 合并两个 groupID 切片并去重。
-func mergeGroupIDs(a, b []int64) []int64 {
-	seen := make(map[int64]struct{}, len(a)+len(b))
-	result := make([]int64, 0, len(a)+len(b))
-	for _, id := range a {
-		if _, ok := seen[id]; !ok {
-			seen[id] = struct{}{}
-			result = append(result, id)
-		}
-	}
-	for _, id := range b {
-		if _, ok := seen[id]; !ok {
-			seen[id] = struct{}{}
-			result = append(result, id)
-		}
-	}
-	return result
-}
-
 // GetTempUnschedulable handles getting temporary unschedulable status
 // GET /api/v1/admin/accounts/:id/temp-unschedulable
 func (h *AccountHandler) GetTempUnschedulable(c *gin.Context) {

backend/internal/handler/admin/group_handler.go

@@ -99,9 +99,9 @@ type CreateGroupRequest struct {
 	FallbackGroupID                 *int64   `json:"fallback_group_id"`
 	FallbackGroupIDOnInvalidRequest *int64   `json:"fallback_group_id_on_invalid_request"`
 	// 模型路由配置（仅 anthropic 平台使用）
-	ModelRouting             map[string][]int64 `json:"model_routing"`
-	ModelRoutingEnabled      bool               `json:"model_routing_enabled"`
-	MCPXMLInject *bool `json:"mcp_xml_inject"`
+	ModelRouting        map[string][]int64 `json:"model_routing"`
+	ModelRoutingEnabled bool               `json:"model_routing_enabled"`
+	MCPXMLInject        *bool              `json:"mcp_xml_inject"`
 	// 支持的模型系列（仅 antigravity 平台使用）
 	SupportedModelScopes []string `json:"supported_model_scopes"`
 	// OpenAI Messages 调度配置（仅 openai 平台使用）
@@ -131,9 +131,9 @@ type UpdateGroupRequest struct {
 	FallbackGroupID                 *int64   `json:"fallback_group_id"`
 	FallbackGroupIDOnInvalidRequest *int64   `json:"fallback_group_id_on_invalid_request"`
 	// 模型路由配置（仅 anthropic 平台使用）
-	ModelRouting             map[string][]int64 `json:"model_routing"`
-	ModelRoutingEnabled      *bool              `json:"model_routing_enabled"`
-	MCPXMLInject *bool `json:"mcp_xml_inject"`
+	ModelRouting        map[string][]int64 `json:"model_routing"`
+	ModelRoutingEnabled *bool              `json:"model_routing_enabled"`
+	MCPXMLInject        *bool              `json:"mcp_xml_inject"`
 	// 支持的模型系列（仅 antigravity 平台使用）
 	SupportedModelScopes *[]string `json:"supported_model_scopes"`
 	// OpenAI Messages 调度配置（仅 openai 平台使用）

backend/internal/server/api_contract_test.go

@@ -650,12 +650,12 @@ func newContractDeps(t *testing.T) *contractDeps {
 	settingRepo := newStubSettingRepo()
 	settingService := service.NewSettingService(settingRepo, cfg)
 
-	adminService := service.NewAdminService(userRepo, groupRepo, &accountRepo, nil, proxyRepo, apiKeyRepo, redeemRepo, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
+	adminService := service.NewAdminService(userRepo, groupRepo, &accountRepo, proxyRepo, apiKeyRepo, redeemRepo, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
 	authHandler := handler.NewAuthHandler(cfg, nil, userService, settingService, nil, redeemService, nil)
 	apiKeyHandler := handler.NewAPIKeyHandler(apiKeyService)
 	usageHandler := handler.NewUsageHandler(usageService, apiKeyService)
-	adminSettingHandler := adminhandler.NewSettingHandler(settingService, nil, nil, nil, nil, nil, nil)
-	adminAccountHandler := adminhandler.NewAccountHandler(adminService, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
+	adminSettingHandler := adminhandler.NewSettingHandler(settingService, nil, nil, nil)
+	adminAccountHandler := adminhandler.NewAccountHandler(adminService, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
 
 	jwtAuth := func(c *gin.Context) {
 		c.Set(string(middleware.ContextKeyUser), middleware.AuthSubject{

backend/internal/service/account_test_helpers_test.go

@@ -0,0 +1,48 @@
+package service
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/tlsfingerprint"
+)
+
+// queuedHTTPUpstream is a test helper that serves pre-loaded responses in order.
+type queuedHTTPUpstream struct {
+	responses []*http.Response
+	requests  []*http.Request
+	tlsFlags  []bool
+}
+
+func (u *queuedHTTPUpstream) Do(_ *http.Request, _ string, _ int64, _ int) (*http.Response, error) {
+	return nil, fmt.Errorf("unexpected Do call")
+}
+
+func (u *queuedHTTPUpstream) DoWithTLS(req *http.Request, _ string, _ int64, _ int, profile *tlsfingerprint.Profile) (*http.Response, error) {
+	u.requests = append(u.requests, req)
+	u.tlsFlags = append(u.tlsFlags, profile != nil)
+	if len(u.responses) == 0 {
+		return nil, fmt.Errorf("no mocked response")
+	}
+	resp := u.responses[0]
+	u.responses = u.responses[1:]
+	return resp, nil
+}
+
+// newJSONResponse creates a simple HTTP response for testing.
+func newJSONResponse(status int, body string) *http.Response {
+	return &http.Response{
+		StatusCode: status,
+		Header:     make(http.Header),
+		Body:       io.NopCloser(strings.NewReader(body)),
+	}
+}
+
+// newJSONResponseWithHeader creates a JSON response with a custom header.
+func newJSONResponseWithHeader(status int, body, key, value string) *http.Response {
+	resp := newJSONResponse(status, body)
+	resp.Header.Set(key, value)
+	return resp
+}

backend/internal/service/antigravity_smart_retry_test.go

@@ -9,8 +9,6 @@ import (
 	"net/http"
 	"strings"
 	"testing"
-	"time"
-
 	"github.com/Wei-Shaw/sub2api/internal/pkg/tlsfingerprint"
 	"github.com/stretchr/testify/require"
 )

backend/internal/service/openai_oauth_service.go

@@ -359,20 +359,6 @@ func (s *OpenAIOAuthService) Stop() {
 	s.sessionStore.Stop()
 }
 
-func (s *OpenAIOAuthService) resolveProxyURL(ctx context.Context, proxyID *int64) (string, error) {
-	if proxyID == nil {
-		return "", nil
-	}
-	proxy, err := s.proxyRepo.GetByID(ctx, *proxyID)
-	if err != nil {
-		return "", infraerrors.Newf(http.StatusBadRequest, "OPENAI_OAUTH_PROXY_NOT_FOUND", "proxy not found: %v", err)
-	}
-	if proxy == nil {
-		return "", nil
-	}
-	return proxy.URL(), nil
-}
-
 func normalizeOpenAIOAuthPlatform(platform string) string {
 	return openai.OAuthPlatformOpenAI
 }