Examine source code of Tab Music Controller

{
  "manifest_version": 2,
  "name": "Tab Music Controller",
  "version": "1.0",
  "description": "Control audio playback across tabs like YouTube, Spotify, and more.",
  "permissions": [
    "tabs",
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9b62aadd-8c84-4e40-b8c9-e694303c4a21}"
    }
  }
}