perf: 90ms improvement: Defer more code in renderer, load state earlier

By deferring more code in the renderer and loading state earlier, we
improve startup time by another 90ms!

Before: 507 unique requires (1270-1280ms)
After: 506 unique requires  (1180-1190ms)

src/main/windows/main.js

@@ -45,18 +45,26 @@ function init (state, options) {
     y: initialBounds.y
   })
 
-  win.once('ready-to-show', function () {
+  win.loadURL(config.WINDOW_MAIN)
+
+  win.once('ready-to-show', () => {
     if (!options.hidden) win.show()
   })
 
-  win.loadURL(config.WINDOW_MAIN)
-
-  if (win.setSheetOffset) win.setSheetOffset(config.UI_HEADER_HEIGHT)
+  if (win.setSheetOffset) {
+    win.setSheetOffset(config.UI_HEADER_HEIGHT)
+  }
 
   win.webContents.on('dom-ready', function () {
     menu.onToggleFullScreen(main.win.isFullScreen())
   })
 
+  win.webContents.on('will-navigate', (e, url) => {
+    // Prevent drag-and-drop from navigating the Electron window, which can happen
+    // before our drag-and-drop handlers have been initialized.
+    e.preventDefault()
+  })
+
   win.on('blur', onWindowBlur)
   win.on('focus', onWindowFocus)