Examine source code of Cast

{
  "manifest_version": 3,
  "name": "__MSG_extensionName__",
  "version": "0.3.1",
  "description": "__MSG_extensionDescription__",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "cast@gianlucamazza.it",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "permissions": [
    "nativeMessaging",
    "activeTab",
    "tabs",
    "storage",
    "contextMenus",
    "notifications",
    "alarms"
  ],
  "background": {
    "scripts": [
      "common/errors.js",
      "background/background.js"
    ]
  },
  "action": {
    "default_title": "__MSG_actionTitle__",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/cast-16.png",
      "32": "icons/cast-32.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "all_frames": true,
      "run_at": "document_idle",
      "js": [
        "content/detect.js"
      ]
    },
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://www.youtube-nocookie.com/*"
      ],
      "all_frames": true,
      "run_at": "document_idle",
      "js": [
        "common/errors.js",
        "content/youtube-button.js"
      ]
    }
  ],
  "icons": {
    "48": "icons/cast-48.png",
    "96": "icons/cast-96.png"
  }
}