use own app protocol impl

src/background.ts

@@ -1,7 +1,6 @@
 'use strict'
 
 import { app, protocol, ipcMain, screen } from 'electron'
-import { createProtocol } from 'vue-cli-plugin-electron-builder/lib'
 import installExtension, { VUEJS_DEVTOOLS } from 'electron-devtools-installer'
 import { setupShortcuts } from './main/shortcuts'
 import { createTray } from './main/tray'
@@ -54,7 +53,6 @@ app.on('ready', async () => {
     }
   }
 
-  createProtocol('app')
   createFileProtocol()
 
   setupConfigEvents()

src/main/app-file-protocol.ts

@@ -1,10 +1,17 @@
 import { protocol, app, ipcMain } from 'electron'
 import { IMPORT_FILE } from '@/ipc/ipc-event'
+import { URL } from 'url'
 import path from 'path'
 import crypto from 'crypto'
 import fs from 'fs'
 
 export function createFileProtocol () {
+  protocol.registerFileProtocol('app', (req, resp) => {
+    const url = new URL(req.url)
+    const pathName = path.join(url.host, url.pathname)
+    resp({ path: path.join(__dirname, pathName) })
+  })
+
   protocol.registerFileProtocol('app-file', (req, resp) => {
     resp({ path: path.join(app.getPath('userData'), 'apt-data/files', req.url.substr('app-file://'.length)) })
   })