Examine source code of Window Session Manager

{
  "manifest_version": 3,
  "name": "Window Session Manager",
  "version": "0.8.1",
  "description": "Treat each window as a named session. Tabs auto-save; open and closed sessions list together, one click to restore.",
  "browser_specific_settings": {
    "gecko": {
      "id": "window-session-manager@carl.l.brandenburg",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "tabs",
    "tabGroups",
    "storage",
    "sessions",
    "cookies",
    "alarms"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "sidebar_action": {
    "default_title": "Sessions",
    "default_panel": "sidebar/sidebar.html",
    "default_icon": "icons/icon.svg",
    "open_at_install": true
  },
  "action": {
    "default_title": "Open Sessions sidebar",
    "default_icon": "icons/icon.svg"
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  }
}