Examine source code of Quick Tab Cleaner

{
  "manifest_version": 3,
  "name": "Quick Tab Closer",
  "version": "1.2",
  "description": "Advanced tab cleaner with close-left/right, same-site cleanup, inactive cleanup, and restore.",
  "action": {
    "default_popup": "popup.html",
    "default_icon": "icons/128x128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs",
    "storage",
    "sessions"
  ],
  "commands": {
    "close_tab": {
      "suggested_key": {
        "default": "Ctrl+Shift+X"
      },
      "description": "Close the current tab"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "quick-tab-closer@local.firefox",
      "strict_min_version": "115.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}