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/dev.mjs

@@ -0,0 +1,67 @@
+/**
+ * 开发模式：先构建主进程/preload，再启动 Vite 渲染进程开发服务器，
+ * 等端口就绪后用 Electron 打开开发地址（支持热更新）。
+ *
+ * 说明：子进程统一使用 stdio: 'inherit'，在受限沙箱中也能正常启动。
+ */
+import { spawn } from 'node:child_process';
+import net from 'node:net';
+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 HOST = '127.0.0.1';
+const PORT = 5174;
+const DEV_URL = `http://${HOST}:${PORT}`;
+
+const viteBin = path.join(root, 'node_modules', 'vite', 'bin', 'vite.js');
+
+const vite = spawn(process.execPath, [viteBin, '--host', HOST, '--port', String(PORT), '--strictPort'], {
+  cwd: root,
+  stdio: 'inherit',
+  env: process.env,
+});
+
+let electron = null;
+
+function cleanup(code = 0) {
+  if (electron && !electron.killed) electron.kill();
+  if (!vite.killed) vite.kill();
+  process.exit(code);
+}
+
+function waitForPort(attempt = 0) {
+  const socket = net.connect({ host: HOST, port: PORT });
+  socket.once('connect', () => {
+    socket.destroy();
+    startElectron();
+  });
+  socket.once('error', () => {
+    socket.destroy();
+    if (attempt > 120) {
+      console.error('[dev] 等待 Vite 开发服务器超时');
+      cleanup(1);
+      return;
+    }
+    setTimeout(() => waitForPort(attempt + 1), 250);
+  });
+}
+
+function startElectron() {
+  console.log(`[dev] Vite 已就绪，启动 Electron -> ${DEV_URL}`);
+  electron = spawn(electronPath, ['.'], {
+    cwd: root,
+    stdio: 'inherit',
+    env: { ...process.env, VITE_DEV_SERVER_URL: DEV_URL },
+  });
+  electron.on('exit', (code) => cleanup(code ?? 0));
+}
+
+vite.on('exit', (code) => {
+  if (code !== 0) console.error(`[dev] Vite 退出，code=${code}`);
+});
+process.on('SIGINT', () => cleanup(0));
+process.on('SIGTERM', () => cleanup(0));
+
+waitForPort();