Unify Harbor error handling across server and client

src/server/singbox.js

@@ -1,6 +1,7 @@
 import fs from 'node:fs';
 import path from 'node:path';
 import { settings } from './config.js';
+import { HarborError } from '../shared/errors.js';
 
 const PROXY_TYPES = new Set(['vless', 'vmess', 'trojan', 'shadowsocks', 'hysteria2']);
 const MIXED_INBOUND = 'mixed-in';
@@ -22,7 +23,7 @@ export function buildGatewayConfig(subscriptionConfig, selectedTag, { clientDire
   const vpnOutbound = directClient
     ? null
     : structuredClone(findOutbound(subscriptionConfig, selectedTag));
-  if (!directClient && !vpnOutbound) throw new Error(`Outbound не найден: ${selectedTag}`);
+  if (!directClient && !vpnOutbound) throw new HarborError('SERVER_NOT_FOUND');
   if (vpnOutbound && !vpnOutbound.tag) vpnOutbound.tag = 'vpn-out';
   if (vpnOutbound?.type === 'vless' && !vpnOutbound.packet_encoding) {
     vpnOutbound.packet_encoding = 'xudp';