Gateway: disable OpenAI HTTP chat completions by default (#686)

* feat(gateway): disable OpenAI chat completions HTTP by default

* test(gateway): deflake mock OpenAI tool-calling

* docs(changelog): note OpenAI HTTP endpoint default-off

src/gateway/gateway.tool-calling.mock-openai.test.ts

@@ -6,6 +6,9 @@ import path from "node:path";
 
 import { describe, expect, it } from "vitest";
 
+import { GatewayClient } from "./client.js";
+import { startGatewayServer } from "./server.js";
+
 type OpenAIResponsesParams = {
   input?: unknown[];
 };
@@ -227,7 +230,6 @@ function extractPayloadText(result: unknown): string {
 }
 
 async function connectClient(params: { url: string; token: string }) {
-  const { GatewayClient } = await import("./client.js");
   return await new Promise<InstanceType<typeof GatewayClient>>(
     (resolve, reject) => {
       let settled = false;
@@ -368,7 +370,6 @@ describe("gateway (mock openai): tool calling", () => {
     process.env.CLAWDBOT_CONFIG_PATH = configPath;
 
     const port = await getFreeGatewayPort();
-    const { startGatewayServer } = await import("./server.js");
     const server = await startGatewayServer(port, {
       bind: "loopback",
       auth: { mode: "token", token },