ci(backend): 添加 errcheck 配置

backend/internal/repository/claude_usage_service.go

@@ -19,7 +19,11 @@ func NewClaudeUsageFetcher() service.ClaudeUsageFetcher {
 }
 
 func (s *claudeUsageService) FetchUsage(ctx context.Context, accessToken, proxyURL string) (*service.ClaudeUsageResponse, error) {
-	transport := http.DefaultTransport.(*http.Transport).Clone()
+	transport, ok := http.DefaultTransport.(*http.Transport)
+	if !ok {
+		return nil, fmt.Errorf("failed to get default transport")
+	}
+	transport = transport.Clone()
 	if proxyURL != "" {
 		if parsedURL, err := url.Parse(proxyURL); err == nil {
 			transport.Proxy = http.ProxyURL(parsedURL)

backend/internal/service/account_usage_service.go

@@ -98,8 +98,10 @@ func (s *AccountUsageService) GetUsage(ctx context.Context, accountID int64) (*U
 	if account.CanGetUsage() {
 		// 检查缓存
 		if cached, ok := usageCacheMap.Load(accountID); ok {
-			cache := cached.(*usageCache)
-			if time.Since(cache.timestamp) < cacheTTL {
+			cache, ok := cached.(*usageCache)
+			if !ok {
+				usageCacheMap.Delete(accountID)
+			} else if time.Since(cache.timestamp) < cacheTTL {
 				return cache.data, nil
 			}
 		}