Examine source code of Timer do Galhofinha

{
  "manifest_version": 2,
  "name": "Timer do Galhofinha",
  "version": "6.5",
  "description": "Alarme, Temporizador e Cronometro com som. Alarme funciona em background.",
  "permissions": [
    "alarms",
    "storage",
    "tabs",
    "notifications"
  ],
  "browser_action": {
    "default_popup": "pages/popup.html",
    "default_title": "Timer do Galhofinha",
    "default_icon": {
      "16": "icons/icon-16.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "background": {
    "scripts": [
      "scripts/background_ff.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "web_accessible_resources": [
    "pages/sound.html",
    "pages/sound.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "timer-galhofinha@manus.ai",
      "strict_min_version": "91.0"
    }
  }
}