feat: Introduce core application structure, configuration, monitoring, and team management features.

backend/internal/api/upload.go

@@ -379,7 +379,8 @@ func fetchAccountID(token string) (string, error) {
 		proxy = cfg.GetProxy()
 	}
 
-	tlsClient, err := client.New(proxy)
+	resolvedProxy := database.Instance.ResolveProxy(proxy)
+	tlsClient, err := client.New(resolvedProxy)
 	if err != nil {
 		return "", fmt.Errorf("创建 TLS 客户端失败: %v", err)
 	}