fix: serialize local-agent heartbeats

local-agent/server.mjs

@@ -7,6 +7,7 @@ import os from "node:os";
 import { join, resolve } from "node:path";
 import { discoverCodexProjectCandidatesInWorker } from "./codex-session-discovery.mjs";
 import { buildCodexTaskExecution } from "./codex-task-runner.mjs";
+import { createSerializedRunner } from "./serialized-runner.mjs";
 
 async function loadConfig(configPath) {
   const raw = await readFile(resolve(configPath), "utf8");
@@ -493,7 +494,7 @@ const runtime = {
   lastProjectDiscoverySummary: null,
 };
 
-async function heartbeat() {
+async function performHeartbeat() {
   try {
     const heartbeatProjects = await resolveHeartbeatProjects(config, runtime);
     const result = await postHeartbeat(config, runtime, heartbeatProjects);
@@ -567,6 +568,8 @@ async function heartbeat() {
   }
 }
 
+const heartbeat = createSerializedRunner(performHeartbeat);
+
 const server = createServer(async (request, response) => {
   if (request.url === "/health") {
     response.writeHead(200, { "Content-Type": "application/json" });