fix gateway probe bad port transport

scripts/gateway-outbound-demo-smoke.mjs

@@ -1,6 +1,8 @@
 #!/usr/bin/env node
 import { spawn } from "node:child_process";
 import { createServer } from "node:net";
+import http from "node:http";
+import https from "node:https";
 import { setTimeout as delay } from "node:timers/promises";
 import assert from "node:assert/strict";
 
@@ -183,26 +185,56 @@ async function waitForJson(url) {
 }
 
 async function getJson(url) {
-  const response = await fetch(url, {
+  return requestJson(url, {
+    method: "GET",
     headers: { accept: "application/json" }
   });
-  const text = await response.text();
-  if (!response.ok) throw new Error(`HTTP ${response.status}: ${text}`);
-  return text ? JSON.parse(text) : null;
 }
 
 async function postJson(url, body) {
-  const response = await fetch(url, {
+  return requestJson(url, {
     method: "POST",
     headers: {
       accept: "application/json",
       "content-type": "application/json"
     },
-    body: JSON.stringify(body)
+    body
+  });
+}
+
+function requestJson(url, { method, headers = {}, body }) {
+  return new Promise((resolve, reject) => {
+    const target = new URL(url);
+    const client = target.protocol === "https:" ? https : http;
+    const payload = body === undefined ? "" : JSON.stringify(body);
+    const request = client.request(target, {
+      method,
+      headers: {
+        ...headers,
+        ...(payload ? { "content-length": Buffer.byteLength(payload) } : {})
+      }
+    }, (response) => {
+      let text = "";
+      response.setEncoding("utf8");
+      response.on("data", (chunk) => {
+        text += chunk;
+      });
+      response.on("end", () => {
+        if ((response.statusCode ?? 0) < 200 || (response.statusCode ?? 0) >= 300) {
+          reject(new Error(`HTTP ${response.statusCode}: ${text}`));
+          return;
+        }
+        try {
+          resolve(text ? JSON.parse(text) : null);
+        } catch (error) {
+          reject(new Error(`non-JSON response: ${error.message}`));
+        }
+      });
+    });
+    request.on("error", reject);
+    if (payload) request.write(payload);
+    request.end();
   });
-  const text = await response.text();
-  if (!response.ok) throw new Error(`HTTP ${response.status}: ${text}`);
-  return text ? JSON.parse(text) : null;
 }
 
 function shellRpc({ id, traceId, command, cwd, timeoutMs }) {