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/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

@@ -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))