main: add context bridge communication example via preload script, set nodeIntegration to false by default, improve security

src/renderer/utils/index.ts

@@ -1,12 +1,10 @@
-import { shell } from 'electron'
-
 export default class Utils {
   static getCurrentLocale(): string {
     return navigator?.language?.split('-')[0] || 'en'
   }
 
   static async openExternal(url: string): Promise<void> {
-    await shell.openExternal(url)
+    await window.mainApi.openExternal(url)
   }
 }