Examine source code of Session Manager & Tab Saver — PureSession

{
  "manifest_version" : 3 ,
  "name" : "Session Manager & Tab Saver — PureSession",
  "short_name" : "PureSession",
  "version" : "1.0.3",
  "description" : "Save, restore and back up tabs in a side panel. Sleep tabs to free memory, remove duplicates, import OneTab. 100% local.",
  "icons" : {
    "16" : "icons/icon16.png",
    "32" : "icons/icon32.png",
    "48" : "icons/icon48.png",
    "128" : "icons/icon128.png"
  },
  "action" : {
    "default_title" : "PureSession — toggle sidebar",
    "default_icon" : {
      "16" : "icons/icon16.png",
      "32" : "icons/icon32.png"
    }
  },
  "sidebar_action": {
    "default_panel": "sidepanel.html",
    "default_title" : "PureSession",
    "default_icon" : {
      "16" : "icons/icon16.png",
      "32" : "icons/icon32.png"
    },
    "open_at_install": true
  },
  "background" : {
    "scripts" : [
      "lib/api.js" ,
      "lib/model.js" ,
      "lib/db.js" ,
      "background.js" 
    ]
  },
  "permissions" : [
    "tabs" ,
    "storage" ,
    "unlimitedStorage" ,
    "alarms" 
  ],
  "host_permissions" : [
    "https://api.gumroad.com/*" 
  ],
  "commands" : {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Alt+Shift+S"
      },
      "description" : "Open PureSession"
    }
  },
  "content_security_policy" : {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@puresession-tabs",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}