fix: keep gateway command in foreground

scripts/dev-gateway.mjs

@@ -26,19 +26,6 @@ const env = { ...process.env, ...rootEnv, ...gatewayEnv };
 if (!env.LISTEN_ADDR) env.LISTEN_ADDR = "127.0.0.1:28187";
 if (!env.GATEWAY_TOKEN) env.GATEWAY_TOKEN = "dev-creatorhub-gateway-token";
 
-const port = env.LISTEN_ADDR.match(/:(\d+)$/)?.[1] ?? "28187";
-try {
-  const response = await fetch(`http://127.0.0.1:${port}/healthz`, {
-    signal: AbortSignal.timeout(1000),
-  });
-  if (response.status === 204 || response.ok) {
-    console.log(`[dev-gateway] 已有 gateway 运行于 127.0.0.1:${port}，直接复用。`);
-    process.exit(0);
-  }
-} catch {
-  // The port is available or belongs to a different service; let the gateway report that clearly.
-}
-
 const gateway = spawn("python3", ["-m", "browser_gateway.server.http"], {
   cwd: root,
   env,