Examine source code of Secret Message Encoder

{
  "manifest_version": 2,
  "name": "Secret Message Encoder",
  "version": "1.0.0",
  "description": "Encode and decode secret messages with multiple encryption methods",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Secret Message Encoder 🕵️"
  },
  "icons": {
    "48": "icon.png"
  },
  "content_security_policy": "script-src 'self' https://api.qrserver.com; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "{dc1b2935-0972-478e-89fb-599c0b83f58b}"
    }
  }
}