Examine source code of Chinese Chess

{
  "manifest_version": 3,
  "name": "离线中国象棋",
  "version": "0.1.0",
  "description": "完全离线运行的 Firefox 桌面端双人中国象棋扩展。",
  "permissions": [
    "storage"
  ],
  "action": {
    "default_title": "打开中国象棋",
    "default_icon": {
      "16": "assets/icon.svg",
      "32": "assets/icon.svg",
      "48": "assets/icon.svg",
      "96": "assets/icon.svg"
    }
  },
  "background": {
    "scripts": [
      "background/window-manager.js"
    ]
  },
  "icons": {
    "16": "assets/icon.svg",
    "32": "assets/icon.svg",
    "48": "assets/icon.svg",
    "96": "assets/icon.svg"
  },
  "content_security_policy": {
    "extension_pages": "default-src 'self'; script-src 'self'; style-src 'self'; img-src 'self' data:; connect-src 'none'; object-src 'none'; frame-src 'none'; base-uri 'none'; form-action 'none'"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "offline-xiangqi-6fc994b4@local.extension",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}