feat(gateway): add scoped proxy egress deployment

telegram-gateway/.env.example

@@ -1,5 +1,8 @@
 # Application
 NODE_ENV=development
+# Optional image build mirrors for networks where deb.debian.org is unavailable.
+DEBIAN_MIRROR=https://deb.debian.org/debian
+DEBIAN_SECURITY_MIRROR=https://deb.debian.org/debian-security
 PORT=3000
 APP_NAME=TelegramUserGateway
 CORS_ORIGINS=
@@ -29,6 +32,14 @@ TDLIB_PATH=/usr/local/lib/libtdjson.so
 TG_API_ID=0
 TG_API_HASH=your_api_hash_here
 
+# 可选默认代理。账号未绑定专属代理时使用；只影响 Telegram TDLib 出站。
+TG_DEFAULT_PROXY_TYPE=
+TG_DEFAULT_PROXY_HOST=
+TG_DEFAULT_PROXY_PORT=
+TG_DEFAULT_PROXY_USERNAME=
+TG_DEFAULT_PROXY_PASSWORD=
+TG_DEFAULT_PROXY_SECRET=
+
 # Rate Limiting
 RATE_LIMIT_DEFAULT_TTL=60000
 RATE_LIMIT_DEFAULT_LIMIT=30