fix(后端): 修复 lint 失败并清理无用代码

修正测试中的 APIKey 名称引用
移除不可达返回与未使用函数
统一 gofmt 格式并处理 Close 错误

backend/internal/config/config.go

@@ -497,9 +497,9 @@ func setDefaults() {
 	viper.SetDefault("gateway.max_body_size", int64(100*1024*1024))
 	viper.SetDefault("gateway.connection_pool_isolation", ConnectionPoolIsolationAccountProxy)
 	// HTTP 上游连接池配置（针对 5000+ 并发用户优化）
-	viper.SetDefault("gateway.max_idle_conns", 240)            // 最大空闲连接总数（HTTP/2 场景默认）
-	viper.SetDefault("gateway.max_idle_conns_per_host", 120)   // 每主机最大空闲连接（HTTP/2 场景默认）
-	viper.SetDefault("gateway.max_conns_per_host", 240)        // 每主机最大连接数（含活跃，HTTP/2 场景默认）
+	viper.SetDefault("gateway.max_idle_conns", 240)           // 最大空闲连接总数（HTTP/2 场景默认）
+	viper.SetDefault("gateway.max_idle_conns_per_host", 120)  // 每主机最大空闲连接（HTTP/2 场景默认）
+	viper.SetDefault("gateway.max_conns_per_host", 240)       // 每主机最大连接数（含活跃，HTTP/2 场景默认）
 	viper.SetDefault("gateway.idle_conn_timeout_seconds", 90) // 空闲连接超时（秒）
 	viper.SetDefault("gateway.max_upstream_clients", 5000)
 	viper.SetDefault("gateway.client_idle_ttl_seconds", 900)

backend/internal/handler/gateway_handler.go

@@ -13,8 +13,8 @@ import (
 
 	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/antigravity"
-	pkgerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/claude"
+	pkgerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/openai"
 	middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
 	"github.com/Wei-Shaw/sub2api/internal/service"

backend/internal/repository/claude_oauth_service.go

@@ -246,13 +246,3 @@ func createReqClient(proxyURL string) *req.Client {
 
 	return client
 }
-
-func prefix(s string, n int) string {
-	if n <= 0 {
-		return ""
-	}
-	if len(s) <= n {
-		return s
-	}
-	return s[:n]
-}

backend/internal/server/middleware/api_key_auth_google_test.go

@@ -113,12 +113,12 @@ func TestApiKeyAuthWithSubscriptionGoogle_QueryApiKeyRejected(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 
 	r := gin.New()
-	apiKeyService := newTestApiKeyService(fakeApiKeyRepo{
-		getByKey: func(ctx context.Context, key string) (*service.ApiKey, error) {
+	apiKeyService := newTestAPIKeyService(fakeAPIKeyRepo{
+		getByKey: func(ctx context.Context, key string) (*service.APIKey, error) {
 			return nil, errors.New("should not be called")
 		},
 	})
-	r.Use(ApiKeyAuthWithSubscriptionGoogle(apiKeyService, nil, &config.Config{}))
+	r.Use(APIKeyAuthWithSubscriptionGoogle(apiKeyService, nil, &config.Config{}))
 	r.GET("/v1beta/test", func(c *gin.Context) { c.JSON(200, gin.H{"ok": true}) })
 
 	req := httptest.NewRequest(http.MethodGet, "/v1beta/test?api_key=legacy", nil)
@@ -137,9 +137,9 @@ func TestApiKeyAuthWithSubscriptionGoogle_QueryKeyAllowedOnV1Beta(t *testing.T)
 	gin.SetMode(gin.TestMode)
 
 	r := gin.New()
-	apiKeyService := newTestApiKeyService(fakeApiKeyRepo{
-		getByKey: func(ctx context.Context, key string) (*service.ApiKey, error) {
-			return &service.ApiKey{
+	apiKeyService := newTestAPIKeyService(fakeAPIKeyRepo{
+		getByKey: func(ctx context.Context, key string) (*service.APIKey, error) {
+			return &service.APIKey{
 				ID:     1,
 				Key:    key,
 				Status: service.StatusActive,
@@ -151,7 +151,7 @@ func TestApiKeyAuthWithSubscriptionGoogle_QueryKeyAllowedOnV1Beta(t *testing.T)
 		},
 	})
 	cfg := &config.Config{RunMode: config.RunModeSimple}
-	r.Use(ApiKeyAuthWithSubscriptionGoogle(apiKeyService, nil, cfg))
+	r.Use(APIKeyAuthWithSubscriptionGoogle(apiKeyService, nil, cfg))
 	r.GET("/v1beta/test", func(c *gin.Context) { c.JSON(200, gin.H{"ok": true}) })
 
 	req := httptest.NewRequest(http.MethodGet, "/v1beta/test?key=valid", nil)

backend/internal/service/billing_cache_service.go

@@ -16,7 +16,7 @@ import (
 // 注：ErrInsufficientBalance在redeem_service.go中定义
 // 注：ErrDailyLimitExceeded/ErrWeeklyLimitExceeded/ErrMonthlyLimitExceeded在subscription_service.go中定义
 var (
-	ErrSubscriptionInvalid = infraerrors.Forbidden("SUBSCRIPTION_INVALID", "subscription is invalid or expired")
+	ErrSubscriptionInvalid       = infraerrors.Forbidden("SUBSCRIPTION_INVALID", "subscription is invalid or expired")
 	ErrBillingServiceUnavailable = infraerrors.ServiceUnavailable("BILLING_SERVICE_ERROR", "Billing service temporarily unavailable. Please retry later.")
 )
 
@@ -73,10 +73,10 @@ type cacheWriteTask struct {
 // BillingCacheService 计费缓存服务
 // 负责余额和订阅数据的缓存管理，提供高性能的计费资格检查
 type BillingCacheService struct {
-	cache    BillingCache
-	userRepo UserRepository
-	subRepo  UserSubscriptionRepository
-	cfg      *config.Config
+	cache          BillingCache
+	userRepo       UserRepository
+	subRepo        UserSubscriptionRepository
+	cfg            *config.Config
 	circuitBreaker *billingCircuitBreaker
 
 	cacheWriteChan     chan cacheWriteTask
@@ -659,28 +659,3 @@ func circuitStateString(state billingCircuitBreakerState) string {
 		return "unknown"
 	}
 }
-
-// checkSubscriptionLimitsFallback 降级检查订阅限额
-func (s *BillingCacheService) checkSubscriptionLimitsFallback(subscription *UserSubscription, group *Group) error {
-	if subscription == nil {
-		return ErrSubscriptionInvalid
-	}
-
-	if !subscription.IsActive() {
-		return ErrSubscriptionInvalid
-	}
-
-	if !subscription.CheckDailyLimit(group, 0) {
-		return ErrDailyLimitExceeded
-	}
-
-	if !subscription.CheckWeeklyLimit(group, 0) {
-		return ErrWeeklyLimitExceeded
-	}
-
-	if !subscription.CheckMonthlyLimit(group, 0) {
-		return ErrMonthlyLimitExceeded
-	}
-
-	return nil
-}

backend/internal/service/gateway_service.go

@@ -1731,7 +1731,6 @@ func (s *GatewayService) handleStreamingResponse(ctx context.Context, resp *http
 		}
 	}
 
-	return &streamingResult{usage: usage, firstTokenMs: firstTokenMs}, nil
 }
 
 // replaceModelInSSELine 替换SSE数据行中的model字段

backend/internal/service/openai_gateway_service.go

@@ -934,7 +934,6 @@ func (s *OpenAIGatewayService) handleStreamingResponse(ctx context.Context, resp
 		}
 	}
 
-	return &openaiStreamingResult{usage: usage, firstTokenMs: firstTokenMs}, nil
 }
 
 func (s *OpenAIGatewayService) replaceModelInSSELine(line, fromModel, toModel string) string {

backend/internal/service/openai_gateway_service_test.go

@@ -72,7 +72,7 @@ func TestOpenAIStreamingTooLong(t *testing.T) {
 	}
 
 	go func() {
-		defer pw.Close()
+		defer func() { _ = pw.Close() }()
 		// 写入超过 MaxLineSize 的单行数据，触发 ErrTooLong
 		payload := "data: " + strings.Repeat("a", 128*1024) + "\n"
 		_, _ = pw.Write([]byte(payload))