feat(desktop-client): 阶段4-6 Electron EXE 客户端（登录/课表/作业/通知/成绩/设置 + Socket.IO 实时 + IndexedDB 离线缓存与自动同步 + electron-builder 打包）

packages/desktop-client/scripts/smoke.mjs

@@ -0,0 +1,35 @@
+/**
+ * Electron 冒烟验证：以 ELECTRON_SMOKE_TEST=1 启动应用（不弹窗），
+ * 主进程会依次校验 preload 桥接、渲染进程挂载、登录页 DOM、
+ * IPC 往返、IndexedDB 缓存读写、断网回退缓存，然后自动退出。
+ *
+ * 前置条件：已执行 npm run build（需要 dist/main 与 dist/renderer）。
+ */
+import { spawn } from 'node:child_process';
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import electronPath from 'electron';
+
+const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
+const required = [path.join(root, 'dist/main/index.js'), path.join(root, 'dist/renderer/index.html')];
+const missing = required.filter((file) => !fs.existsSync(file));
+
+if (missing.length > 0) {
+  console.error('[smoke] 缺少构建产物，请先执行构建：');
+  console.error('  pnpm --filter @classhelper/desktop-client build');
+  for (const file of missing) console.error(`  缺失: ${path.relative(root, file)}`);
+  process.exit(2);
+}
+
+console.log('[smoke] 启动 Electron 冒烟验证...\n');
+const child = spawn(electronPath, ['.'], {
+  cwd: root,
+  stdio: 'inherit',
+  env: { ...process.env, ELECTRON_SMOKE_TEST: '1' },
+});
+
+child.on('exit', (code) => {
+  console.log(`\n[smoke] Electron 退出，code=${code ?? 1}`);
+  process.exit(code ?? 1);
+});