Examine source code of Tab Runner

{
  "manifest_version": 3,
  "name": "Tab Runner",
  "version": "1.0.4",
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA3wcEmi+r5tKT6FCu2wiEhkj9fW27WxuJ/BvqMHMK/hc0jB7GXqxHML2vb9MGXtqjd1xhQHYOAemWFmw+Tzslua2Bo7mdCOmwY7AYtBweJwIVpuAjrlRk8EsvjdDVS3fDBSvEjc5JxTgObaTGjHkUcb/fhgyLvTLrqgs/+nwcPDLJJrVJpTdP7VaXyw/cujxWVnCzLzpLBimdd56uigXZduWA99efbWJzcG5BZVEqNbrWSCFqACoAY9s+urY+jLZsKHzQV2Zp6cm5HrtoYZf1v6/JwP+R+W/cd1kdJYW3t2meHhrqPeL7fCHieb/eaie2gDcYQS8d5TQDJa6mv6KaTwIDAQAB",
  "description": "Create, save, run, stop scripts that open tabs in the background without stealing focus.",
  "permissions": [
    "tabs",
    "storage",
    "alarms",
    "webRequest",
    "webRequestBlocking"
  ],
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "96": "icons/icon96.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_title": "Tab Runner",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png"
    }
  },
  "background": {
    "scripts": [
      "service_worker.js"
    ],
    "type": "module"
  },
  "host_permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "mobile_emulation.js"
      ],
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "bg-tab-runner@local",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}