register with engine

apps/remix-ide/src/app.js

@@ -448,7 +448,8 @@ Please make a backup of your contracts and start using http://remix.ethereum.org
     test,
     filePanel.remixdHandle,
     filePanel.gitHandle,
-    filePanel.hardhatHandle
+    filePanel.hardhatHandle,
+    filePanel.slitherHandle
   ])
 
   if (isElectron()) {

apps/remix-ide/src/app/panels/file-panel.js

@@ -9,6 +9,7 @@ import { checkSpecialChars, checkSlash } from '../../lib/helper'
 const { RemixdHandle } = require('../files/remixd-handle.js')
 const { GitHandle } = require('../files/git-handle.js')
 const { HardhatHandle } = require('../files/hardhat-handle.js')
+const { SlitherHandle } = require('../files/slither-handle.js')
 const globalRegistry = require('../../global/registry')
 const examples = require('../editor/examples')
 const GistHandler = require('../../lib/gist-handler')
@@ -59,6 +60,7 @@ module.exports = class Filepanel extends ViewPlugin {
     this.remixdHandle = new RemixdHandle(this._deps.fileProviders.localhost, appManager)
     this.gitHandle = new GitHandle()
     this.hardhatHandle = new HardhatHandle()
+    this.slitherHandle = new SlitherHandle()
     this.registeredMenuItems = []
     this.removedMenuItems = []
     this.request = {}