macOS 架构：主进程 / preload 桥 / 渲染进程

用户操作（渲染进程）
   │  window.niPaasIMBridge.imlib.sendTextMessage(1, targetId, text)
   ▼
preload（固定白名单）→ ipcRenderer.invoke('ni-paas-im:invoke', {ns:'imlib', op, args})
   ▼
主进程 registerIpc → service（IMLib 客户端 + 本地 SQLite）
   │  client.sendTextMessage(...) / 本地落库
   ▼
IM 服务端（WebSocket）
   │  下行消息 / 回执 / 会话变更
   ▼
主进程事件 → ipcMain 广播 'ni-paas-im:event' {event,payload,seq,ts} 到订阅窗口
   ▼
preload onEvent → 渲染进程更新宿主 UI

import { app, BrowserWindow, ipcMain } from 'electron';
import { join } from 'node:path';
import { createRequire } from 'node:module';
import { initService, Events } from '@ni-paas-im/electron/main';
import { registerIpc } from '@ni-paas-im/electron/main/ipc';

const require = createRequire(import.meta.url);
let win;
let service;
let bridge;

async function createWindow() {
  win = new BrowserWindow({
    width: 1280,
    height: 800,
    titleBarStyle: 'hiddenInset',
    trafficLightPosition: { x: 16, y: 16 },
    webPreferences: {
      preload: join(require.resolve('@ni-paas-im/electron/package.json'), '..', 'src', 'preload', 'index.mjs'),
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: false,                       // ESM preload 只在非沙箱渲染进程加载
    },
  });
  await win.loadFile('renderer/index.html');
}

app.whenReady().then(async () => {
  service = initService({
    appkey: 'demo',
    serverUrl: 'https://im.example.com',
    dbPath: app.getPath('userData'),        // 目录
  });
  bridge = registerIpc({ ipcMain, service });   // service 传 initService() 返回值本身

  // 宿主侧（通知 / 托盘 / 角标）可直接订阅主进程事件
  service.client.addEventListener(Events.CONNECTED, (payload) => console.log('connected', payload.userId));
  service.client.addEventListener(Events.MESSAGES, ({ messages }) => console.log('messages', messages.length));

  await createWindow();
});

app.on('window-all-closed', () => {
  if (bridge) bridge.dispose();
  if (service) service.destroy();
  if (process.platform !== 'darwin') app.quit();
});
app.on('activate', () => { if (BrowserWindow.getAllWindows().length === 0) createWindow(); });