feat(pm2): update PM2 configuration and introduce new start script

- Updated PM2 version to 6.0.14 in package.json and pnpm-lock.yaml for improved stability.
- Changed interpreter for PM2 processes to use `process.execPath` for consistency.
- Added a new `start:pm2` script in package.json to streamline PM2 process management.
- Updated README to reflect changes in PM2 usage and instructions for starting the application.

scripts/pm2.mjs

@@ -0,0 +1,48 @@
+#!/usr/bin/env node
+/**
+ * Run the same PM2 binary control.js `require("pm2")` uses.
+ * A global `pm2` 7.x talking to an in-memory 6.x daemon pegs CPU on start.
+ */
+import { spawn, spawnSync } from "node:child_process";
+import { createRequire } from "node:module";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
+const require = createRequire(
+  path.join(root, "packages/server/package.json"),
+);
+const pm2Root = path.dirname(require.resolve("pm2/package.json"));
+const pm2Bin = path.join(pm2Root, "bin/pm2");
+const args = process.argv.slice(2);
+
+function run(pm2Args, opts = {}) {
+  return spawnSync(process.execPath, [pm2Bin, ...pm2Args], {
+    cwd: root,
+    encoding: "utf8",
+    ...opts,
+  });
+}
+
+const cmd = args[0];
+if (cmd === "start" || cmd === "restart" || cmd === "reload") {
+  const probe = run(["ls"], { stdio: ["ignore", "pipe", "pipe"] });
+  const text = `${probe.stdout ?? ""}${probe.stderr ?? ""}`;
+  const mem = text.match(/In memory PM2 version:\s*(\S+)/);
+  const loc = text.match(/Local PM2 version:\s*(\S+)/);
+  if (mem && loc && mem[1] !== loc[1]) {
+    console.error(
+      `[jflow] PM2 daemon ${mem[1]} != CLI ${loc[1]}. Killing the daemon so control.js and the CLI share one version.`,
+    );
+    run(["kill"], { stdio: "inherit" });
+  }
+}
+
+const child = spawn(process.execPath, [pm2Bin, ...args], {
+  cwd: root,
+  stdio: "inherit",
+});
+child.on("exit", (code, signal) => {
+  if (signal) process.kill(process.pid, signal);
+  process.exit(code ?? 1);
+});