Examine source code of GridGhost

{
  "manifest_version": 3,
  "name": "GridGhost",
  "version": "1.0.0",
  "description": "Overlay configurable design grids on any page for layout QA and spacing checks.",
  "icons": {
    "48": "assets/icon-48.png",
    "96": "assets/icon-96.png",
    "128": "assets/icon-128.png"
  },
  "action": {
    "default_title": "GridGhost",
    "default_popup": "ui/popup.html",
    "default_icon": {
      "48": "assets/icon-48.png"
    }
  },
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8f59f809-4de2-42ab-bf35-ad5f6bf7ad18}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}