feat: bootstrap Electron desktop shell for Fabric frontend

main.js

@@ -0,0 +1,25 @@
+const { app, BrowserWindow } = require('electron')
+
+function createWindow() {
+  const win = new BrowserWindow({
+    width: 1280,
+    height: 840,
+    webPreferences: {
+      contextIsolation: true,
+    },
+  })
+
+  const url = process.env.FABRIC_DESKTOP_URL || 'file://' + __dirname + '/offline.html'
+  win.loadURL(url)
+}
+
+app.whenReady().then(() => {
+  createWindow()
+  app.on('activate', () => {
+    if (BrowserWindow.getAllWindows().length === 0) createWindow()
+  })
+})
+
+app.on('window-all-closed', () => {
+  if (process.platform !== 'darwin') app.quit()
+})