Examine source code of Text Case Converter

{
  "manifest_version": 2,
  "name": "Text Case Converter",
  "version": "1.0",
  "description": "Transform text into various case formats and copy the result",
  "permissions": [
    "clipboardWrite"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Text Case Converter"
  },
  "icons": {
    "48": "icon.png"
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "{0031702f-03c6-46c0-a99c-650a06806b32}"
    }
  }
}