Examine source code of Paint Calculator

{
  "manifest_version": 2,
  "name": "Paint Calculator",
  "version": "1.0",
  "description": "Calculate paint requirements based on surface area, spreading rate, and number of coats.",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "background": {
    "page": "background.html"
  },
  "content_security_policy": "script-src 'self'; object-src 'none';",
  "browser_specific_settings": {
    "gecko": {
      "id": "{818b9106-9e41-400c-a12b-f9cfb98adf69}"
    }
  }
}