Examine source code of 800% Sound Volume

{
  "manifest_version": 3,
  "name": "800% Sound Volume",
  "version": "1.4.1",
  "description": "Professional audio boost extension with per-site persistence. Default 100% volume, boost up to 800% with crystal clear quality.",
  "permissions": [
    "storage",
    "tabs",
    "scripting",
    "webNavigation"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "800% Sound Volume"
  },
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "128": "icons/128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "content.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "800soundvolume@devlabs.com",
      "data_collection_permissions": {
        "required": [
          "websiteActivity"
        ],
        "optional": []
      }
    }
  }
}