Examine source code of VN Word Drill

{
  "manifest_version": 2,
  "name": "VN Word Drill",
  "version": "1.0",
  "description": "Fast daily drill: Vietnamese verbs → English. Popup quiz for quick practice.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "VN Word Drill"
  },
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e2edbfe7-0ea3-4de0-8317-ac137a43314a}",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}